First trimester: key stages
The first trimester begins on the first day of your last period and lasts until the end of week 12. This means that by the time you know for sure you're pregnant, you might already be five or six weeks pregnant!
A lot happens during these first three months. The fertilised egg rapidly divides into layers of cells and implants in the wall of your womb where it carries on growing. These layers of cells become an embryo, which is what the baby is called at this stage.
During this trimester, your baby grows faster than at any other time. By six weeks, a heartbeat can usually be heard and by the end of week 12, your baby's bones, muscles and all the organs of the body have formed. At this point, your baby looks like a tiny human being and is now called a fetus. He or she will even be practising swallowing!
When am I due?
When will I see a midwife?
Your first midwife appointment (also known as antenatal appointment) is the 'booking' appointment. This usually happens between week 8 and 10 of your pregnancy. Find out how to register with a midwife and when your appointments will be here.
Keeping your baby safe
There are some things that you can do during pregnancy that have an effect on your baby. Find out about them by clicking the link below.
Not sure whether you are pregnant?
Find out about the symptoms that mean you may be pregnant here.
Your physical and mental health in pregnancy
Don't forget that your mental health is just as important as your physical health. It's normal to feel some anxiety and stress but it shouldn't be ongoing. If what you’re feeling isn’t normal for you, talk to your GP or midwife about it. They are there to help.
Exercise, such as yoga, has been shown to reduce anxiety and is a great way to stay active during your pregnancy, too.
Track your baby's development
Sign up to a free pregnancy email from our midwives to track your baby's development and give you reminders of all you need to know through the nine months of pregnancy. Click here to sign up.
Congratulations on your exciting news! Tommy’s midwives are here to guide you through every stage of your pregnancy and help you get to know your growing baby.
It’s week five and your baby’s tiny face is already starting to form - the beginnings of a tiny nose and eyes are already taking shape.
By the end of this week your baby will have grown to the size of an orange pip.
Your baby, who was once the size of bean, is now the size of a grape.
Here comes a growth spurt: Your little one will double in size this week.
Measuring about 22mm long, your baby is now as big as a strawberry.
Your uterus is the size of a large orange now, and your baby is around 3cm long.
You're now coming up to the end of the first trimester and your baby is starting to look like a baby! Your bump may start to show soon.
It’s been a busy few weeks: Everything is now in place - the organs, limbs, bones and muscles are in place and growing.
NHS Choices. Your pregnancy week by week http://www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-week-by-week.aspx#close (Page last reviewed: 28/02/2017 Next review due: 28/02/2020)
Macdonald S, Magill-Cuerden J (2012) Mayes’ Midwifery, 14th edition, London, Ballière Tindall
NICE (2008) Antenatal care for uncomplicated pregnancies, NICE Clinical Guidelines 62. National Institute for Health and Care Excellence http://publications.nice.org.uk/antenatal-care-cg62Hide details
ℹLast reviewed on June 28th, 2018. Next review date June 28th, 2021.
By Anonymous (not verified) on 13 May 2017 - 18:33
Hello I'm 37 and have PCOS. It took 3 years and IVF to conceive my 19 month old daughter, who I still breastfeed twice a day. I developed post natal hypothyroidism. I recently started metformin to TTC. Today by some miracle I got a positive home pregnancy test-I am 4w4d. This week I also got a call from the doctors telling me to reduce my thyroxine as I've gone hyperthyroid now. TSH 0.07, T4 19.2 and T3 4.4. It'll take 4 weeks for my reduced size to take effect. My sister has had two miscarriages (you have helped her, thank you) and has just been found to be hyperthyroid. Whilst I am over the moon and staggered that I have conceived naturally, I am so anxious about miscarriage. I've had very light brown (barely a tint) discharge since 10dpo and I had one red spot at 10dpo. All pregnancies are precious and this one is a miracle to me - I need to know what I can do to ensure my thyroid levels don't risk my pregnancy. I've some progesterone left over from IVF so I'm going to use them up for the next week. Also, should I stop breastfeeding my daughter? Thank you so much-it's Saturday so my doctors are shut (and are not great with endocrinology or fertility issues)
By Midwife @Tommys on 15 May 2017 - 13:12
Hello and congratulations on your pregnancy. I would suggest that you make an appointment to see your GP as soon as possible and discuss the thyroid levels in the context of the pregnancy.
In the mean time I cannot advise that you take the progesterone tablets that you have left over. Although the BNF states that these tablets are not known to be harmful, studies have shown that progesterone tablets do not really prevent miscarriage. In addition the medication may require storage in a fridge or cool area to maintain it's potency. In a spontaneous pregnancy it is thought that the ovaries will produce enough progesterone to maintain the pregnancy naturally.
How lovely that you are still feeding your daughter. You can continue with this for as long as you and she wants to. You may find of course that she instinctively stops on her own. Some people believe that the taste changes in a pregnancy and the toddler no longer wants to feed. All the best Tommy's midwives x
By Anonymous (not verified) on 12 May 2017 - 14:43
Hi,my last period was on 12th April and lasted for 3days which is not suppose to be so,my period normally last for 5days,untill now i hve not seen my period till now which suppose to come on the 11 (bin yesterday),i don't know if am pregnant cos feeling fuller nd bloat....though,i've not done d pregnancy test....
But,could it be am pregnant?
By Midwife @Tommys on 15 May 2017 - 12:38
Sometimes periods can be irregular and this is not something to worry about but if you think you could be pregnant I would suggest that you do a pregnancy test to confirm either way. x
By Nancy (not verified) on 10 May 2017 - 07:42
I had my last menses around 4th April 2017 and ended on the 10th of April... I have not seen my menses this month and today is 10th May will it be a pregnancy because I tasted positive when I did a
home test ..how old is the pregnancy now
By Midwife @Tommys on 10 May 2017 - 09:21
Using our pregnancy calculator below, you can find out roughly how many weeks you are by putting in the date of the first day of your last menstrual period, as well as your average length of menstrual cycle- this will calculate a rough due date and how many weeks pregnant you are currently.
Congratulations! Please do take care of yourself!
By Lesley (not verified) on 7 May 2017 - 18:56
I have very recently found out I am pregnant after several attempts at IVF. I am 38 and currently 4wks 3days pregnant. I had a missed miscarriage at 10 weeks in Jan 16 following a frozen embryo transfer. Tests on the baby identified no abnormalities. I had swabs taken when being treated at the hospital which identified bacterial vaginosis and e-coli. I had anti biotic treatment for this. As I am pregnant again I am terrified that I may have BV again and that this had some impact on my last miscarriage. I went to my GP yesterday and had swabs taken. I have been advised I may be prescribed metronidazole if BV is identified however I am very concerned about taking any medication, particularly in the first trimester. However I am also scared that if I do not have treatment I may be more susceptible to another miscarriage. What are current recommendations regarding antibiotics in pregnancy and BV in pregnancy. I have been using Balance Activ BV gel as it says it is safe in pregnancy. Would this be a safe and effective alternative to antibiotics?
Thank you, Lesley
By Midwife @Tommys on 8 May 2017 - 16:18
Thank you for your comment. Congratulations on your pregnancy and I hope everything goes well for you
I understand your concerns about taking medication in pregnancy,
"If BV develops in pregnancy, it may increase the risk of pregnancy-related complications, such as premature birth or miscarriage. However, this risk is small and appears more significant for women who have had these complications in a previous pregnancy. BV causes no problems in the vast majority of pregnancies.
As a precaution, you should contact your GP if you're pregnant and you begin to have vaginal discharge (although discharge can be a normal part of pregnancy)."
If you do have BV, I would advise that you consider taking Metronidazole if prescribed; medications are not usually prescribed in pregnancy unless there is a risk to your health if you do not take them so please be guided by your GP's advice
As you are using a BV gel, please also be aware of the following facts to help you make a decision whether or not to take metronidazole
"Vaginal pH correction treatments are a relatively new way of treating BV. These usually involve applying a gel to the inside of your vagina that changes the acid balance, making it a less hospitable environment for harmful bacteria. Most vaginal pH correction treatments are available over the counter from pharmacists.
However, it's not clear how effective these treatments are for treating BV. Some studies have suggested they may help, whereas others suggest they're either ineffective or less effective than antibiotics"
I have attached 2 links that have additional information that may help you
Hope this helps
Please contact us again or call our helpline for further advice
0800 0147 800
By Anonymous (not verified) on 11 May 2017 - 10:58
Thank you so much Marianne.
By Kerry (not verified) on 6 May 2017 - 16:46
My last period was the 14 of march I took a pregnancy test an it came out positive .So my concern is how many week can I ne pregnant
By Midwife @Tommys on 8 May 2017 - 11:50
Thank you for your query. As your last period was 14th march, you are currently 7 weeks and 6 days pregnant.
I hope everything is going well and would encourage you to either contact your GP or local maternity unit so that you can start your pregnancy care. Make sure you are staying healthy-by having a healthy diet, following safe eating in pregnancy advice and taking folic acid supplements for pregnancy. I have attached some links that you may find helpful
Please do not hesitate to contact us for further information or call our helpline 0800 0147 800
By Abosede ogunsola (not verified) on 10 Aug 2017 - 19:22
my last periods was the 9 July
By Midwife @Tommys on 26 Apr 2017 - 09:38
Hi please get back in contact if you need advice as your message is incomplete.
By Janet (not verified) on 25 Apr 2017 - 09:04
I had my last period on 25th March and unprotected sex on de 6th of April. I took post in or 2 after twelve ours . I've had a posi
By Anonymous (not verified) on 24 Apr 2017 - 10:44
I m pregnant and uts my 6 week bt i m not having any splecial feeling like vomiting. Is it ok wid my pregnancy
By Midwife @Tommys on 24 Apr 2017 - 13:23
Congratulations on your pregnancy.
Every woman id different and experiences pregnancy differently. For some that means a lot of nausea and vomiting and for some none at all. Try not to worry - you may be one of the lucky ones to not get the nausea and vomiting, or you may find that as the pregnancy progresses you start to feel it.
Enjoy your pregnancy and if you haven't already start taking Folic Acid and Vitamin D supplements as well as visiting your GP or midwife for antenatal care and advice.
By Anonymous (not verified) on 23 Apr 2017 - 10:22
My depo provera wore off before my next injection was due , I had my period and was just wondering if there is any chance I could be pregnant , I've been feeling dizzy and feeling sick all day for the past week and I passed out once . I had my injection on the 18/4/17 , if I am pregnant can the injection harm the baby ??
By Midwife @Tommys on 24 Apr 2017 - 09:54
Hi - thanks for your message.
Its difficult to say if you are or aren't pregnant without a positive pregnancy test. Please visit your GP who can advise and maybe able to carry out a pregnancy test if you aren't able to - but also for the symptoms you have had too.
If you would like to discuss in more detail please feel to contact us here at Tommy's Pregnancy Line on 08000147800 or via email [email protected]
By Brigitte (not verified) on 21 Apr 2017 - 20:03
I took pregnant test 20th april and found im pregnant..my last period was 15thmarch..how many weeks my pregnancy is?..Also im very stressing because i have problem with sciatic pain/low back pain..is this will be the risk to my pregnancy?..
By Midwife @Tommys on 24 Apr 2017 - 09:49
Hi, Congratulations on your pregnancy and also for finding our site which will help you over the next months.
If the first day of your last period (your LMP) was on 15/03/2107 then you would around 5+5 weeks pregnant - depending on how long your cycle is.
If you haven't already please start taking folic acid and vitamin d supplements and visit your GP for a check and to be referred for antenatal care.
I'm sorry to hear you have sciatic/back pain - neither are a risk to your pregnancy but you may find that you may find the discomfort increasing - again visit your GP early for advice and support.
Good luck for the coming months!
By Anonymous (not verified) on 20 Apr 2017 - 08:37
Hey there :) i found out that i am pregnant obly yesterday and i am super exited for it. But today i am starting to have a bit of cramps and i am very scared about it i am nearly 7 weeks in (6 weeks 6 days).... i am so scared that i will loose my baby .. is it normal to have cramps or a little bit of pain?
By Midwife @Tommys on 20 Apr 2017 - 09:56
Hi, Congratulations on your pregnancy and also for finding our site which will help you over the next months. It isn't uncommon to experience some mild period like pain which is usually attributed to implantation, or occasional sharp pain where the ligaments are stretching. If the symptoms don't resolve or if they get any worse please see your GP for advice.
By Hemamalini (not verified) on 16 Apr 2017 - 16:00
Hi Good eve,
I am 11 weeks now and no heart beat found when scanned. What should be done to bring the heart beat. I am so scared and under medication to induce heart beat. Till he many weeks I should wait and what is the maximum week ?
By Midwife @Tommys on 18 Apr 2017 - 09:51
Hi there - I'm sorry to hear you have been told that there is difficulty in finding baby's heart activity during an early pregnancy scan. In order to advise I would need some more information and clarification of a few details - please contact us either via email [email protected] or on our Pregnancy Helpline 08000147800 so that we an offer confidential support and advice.
By Anonymous (not verified) on 10 Apr 2017 - 10:53
Hi ! I am Pregnant and almost 8 weeks. Had issues with my partner because he said he isn't ready financially. I cried and stressed a lot during my 3-4 weeks period, could this have affected the baby in anyway?
By Midwife @Tommys on 10 Apr 2017 - 11:01
Hi there. Congratulations on your pregnancy. And I am sorry to hear that you have had a difficult time with your partner recently too.
Stress in pregnancy is very tough to deal with, but will not physically harm your baby's growth or well-being. I hope that you partner is being more supportive now and that you have a good friend and family support network too. Please do speak to your GP and Midwife about any ongoing anxiety during your pregnancy as they will be able to support you with more appointments as well as referrals for additional support should you want or need it. Asking for help is always a good thing to do if you are worried or concerned during pregnancy. Do also feel free to call us on our pregnancyline or email us privately on [email protected] We are not counselors, but midwives with a friendly ear, regardless of the situation. Please take good care of yourself.
By confused (not verified) on 8 Apr 2017 - 23:48
Had intercourse with hubby on 26th january.i didn't see my period again till February ending and it has bin regular.could I really be pregnant because I think I am supposed to see the period before February ending.i have not really had any prenancy symptons..just confused...could I be pregnant?
By Midwife @Tommys on 10 Apr 2017 - 09:35
Hi there. It is a little difficult to know. Have you done a pregnancy test at all?
If you are not pregnant, then it would be sensible to go to your GP to get a referral to a gynae clinic to be reviewed. Sometimes, alterations on your menstrualy cycle pattern can be triggered by something else and so it is best to get it checked out if this is the case. Take good care of yourself
By scared (not verified) on 7 Apr 2017 - 15:32
hi just dnt know wats going wit me ddnt see my periods for 3 months but testing neg I dd 4 test already n I have abdominal pains n sore breast, when I visited a clinic the nurse said I have infection then gave me some treatment but still no change could I be pregnant?
By Midwife @Tommys on 7 Apr 2017 - 15:47
Hi, I would suggest if your symptoms are continuing and you have completed the course of treatment prescribed to you then you need to return to your GP to be reviewed and further investigations. It is very unlikely that you are pregnant if you have continued to have negative pregnant tests however it can be possible but it is important to make sure the infection is addressed too.
By Marylynne (not verified) on 6 Apr 2017 - 22:31
Hi dear, My name is Mary I feel pregnant yet testing negative. I had bleeding for 2 days starting 22/3/2017 and took the final test on 28/04/2017 but came out neg. But till the current moment have not testex
By Midwife @Tommys on 7 Apr 2017 - 13:18
Hi Mary, if you think you maybe pregnant it is a good idea to repeat a pregnancy test as the last one may have been a bit early and no sensitive enough to pick up on a possible pregnancy. I am not sure what symptoms you are experiencing or how you feel pregnant but if that continues with a negative test then you can see your GP who can review the symptoms.
By esyluv (not verified) on 26 Mar 2017 - 12:53
good day, I have been having normal signs of pregnancy and my mid wife keeps giving me lots of medicines as if I'm too sick.
I'm scared that the medicine might affect my baby cos it's too much.
I'm about seven weeks pregnant.
By Midwife @Tommys on 27 Mar 2017 - 09:45
Your midwife would only suggest certain medication that is safe for you to take in pregnancy if you really needed it. Also, midwives do not give out medication, unless it has been prescribed by an Obstetric doctor first. Feel free to contact us via email or telephone ([email protected] or 0800 0147800) to speak to a midwife in a more private way.
By Anonymous (not verified) on 13 Mar 2017 - 15:57
HEY THERE, MY friend Says she missed her 2nd depo shot on 13th Feb and on 24th Feb she had unprotected sex,so she scared she might be pregnant is the any chance of her to be pregnant?????
By Midwife @Tommys on 13 Mar 2017 - 16:36
It is really important when using Depo-Provera injections as a form of contraception that the injections are given on time. If it is overdue there is a possibility of a pregnancy . There is good information available on the sexual health charity website. http://www.fpa.org.uk/contraception-help/contraceptive-injections . Hope this helps
By Anonymous (not verified) on 9 Mar 2017 - 09:16
I've been on the nur isterate injection for 6 months. I stopped it now 2 months. I've been getting symptoms of pregnancy like very sore breasts nausea no vomiting and stomach cramps.. My last period was on the 13th of Feb... I tested 2 days back and got a negative result was it to early to test
Could I be pregnant?
By Midwife @Tommys on 9 Mar 2017 - 10:08
Hi, Yes, it is too early to confirm a pregnancy if your last menstrual period was 13/2/17. If you are wanting to become pregnant don't forget to look at our link for preconception care. https://www.tommys.org/pregnancy-information/getting-pregnant/are-you-ready-conceive
BW Tommy's midwives
By Anonymous (not verified) on 8 Mar 2017 - 16:23
Hi, I am around 6 weeks pregnant and I occasionally get light craping pains in my lower back and around my hips, is this normal? I have no bleeding. This is my second pregnancy but the 1st was 8 years ago and it's difficult to remember.
Another question - we have guinea pigs kept indoors, do these pose a threat to an unborn baby?
By Midwife @Tommys on 9 Mar 2017 - 09:53
Hi, Mild cramping pains are not unusual in pregnancy. Each woman and each pregnancy is different. It is reassuring that you have no bleeding. Try gentle exercising and keep yourself moving.
There is no reason to be concerned about guinea pigs although it would be good practice to wear gloves when cleaning them out and also to ensure excellent hand hygiene after handling them. Our link on toxoplasmosis explains why cats are thought to be the animals that transmit this infection in their faeces. https://www.tommys.org/pregnancy-information/i%E2%80%99m-pregnant/antenatal-care/infections-avoid-pregnancy/toxoplasmosis-pregnancy
Hope this helps. Tommy's midwives
By jess (not verified) on 8 Mar 2017 - 10:45
Hi, i have been off my birthcontrol two weeks ago and me and the hubby had grown up games a day before i stopped taking my tablets, last week i had no bad feelings or symptoms at all but this week i feel rough as hell, i have had headaches been more moody been over sexual (tmi) had felt sick yesterday morning (not had that today). i would just like to know if i should buy a test or leave it down to my bc, i have read that some women it could take months/years to conceive and others within the month of coming off them, please help me someone lol.
By Midwife @Tommys on 8 Mar 2017 - 14:48
I wonder if the symptoms you are experiencing are side effects of coming off the pill.
Certainly a peak in interest in sex is really common after coming off the pill as in your natural cycle there is a surge in testosterone. (Women talk about having a lower sex drive on the pill).
You could also be more moody after stopping it. Some women also report headaches, breast tenderness and nausea.
After stopping the pill you can technically ovulate within a week and sperm can live in a woman's body for 5 days so if you weren't using an alternative form of contraception you could be pregnant. My advice would be to buy a pregnancy test and test when it is 3 and a half weeks since you had sex when coming off the pill. Your periods may take a little while to regulate (1-3 months approximately) so even more reason to have an alternative form of contraception if you aren't quite ready to start trying for a baby.
I hope this helps.
By CC (not verified) on 7 Mar 2017 - 13:28
Hi, I'm 8 weeks & 2 days pregnant although I don't feel pregnant! Is this normal?
I'm also sleeping for around 16 + hours at a time over the last few days, whereas I was only getting about 2 hours sleep in the weeks prior. Is 16 + hours of sleep & lack of energy normal at this early stage?
By Midwife @Tommys on 7 Mar 2017 - 14:38
Congratulations on your pregnancy! This early stage can be very tiring and every pregnant woman experiences different symptoms which can vary hugely and some never really get any noticeable symptoms. Sleeping a lot more can be normal and part of early pregnancy, however it can also be a sign of low iron levels and sometimes a thyroid problem, if this has been continuing then I would recommend you contacting your GP or midwife. If you have had your booking appointment then they should have taking some blood tests from you, if you chase these up this will tell you your iron levels. If you have not yet had your booking then hopefully this will be soon. If you have any breathlessness or pain then I would advise for you to see your GP as soon as possible. I hope this helps, Tommy's midwives.
By Anonymous (not verified) on 15 Mar 2017 - 16:33
Hi, Thank you for your above response.
I've been for my booking appointment today & have left feeling totally confused......I had both an external & internal scan & they've said that I'm only 4 weeks pregnant (too early for the booking appointment checks) although checking when I tested posititve, it was 8 weeks ago.
How is this possible - is something wrong?
Thanks again for your help
By Midwife @Tommys on 16 Mar 2017 - 09:57
Hi, I think i just replied to you on another page.
You need to work out the date of the first day of your last menstrual period, and your average cycle length using our pregnancy calculator to estimate your gestation and current due date.
Once you know this, please go back to your GP to discuss the results and get another date for booking and ultrasound scan. Sometimes dating pregnancies can be confusing, but it is important to know roughly how pregnant you are so that you receive the right care in a timely manner. Take care of yourself
By Midwife @Tommys on 1 Mar 2017 - 14:29
Hi, thank you for your post. It sounds like the bleeding was a really frightening experience. I understand from your message that you went on to have an early scan and you were told that 'there was a pregnancy but it was not really formed' It is such a shock when you experience unexpected bleeding and then end up being scanned. In times of intense stress we don't retain information as we are in shock. Is there a plan for you to return to the hospital for another scan? In some instances it may be too early to detect a heartbeat and confirm a viable pregnancy so returning to be rescanned in 10-14 days can give more information as the developing embryo would be visible as would a heartbeat.
I hope that this has been scheduled for you? You might like to look at this website for more information.
Please keep in contact and if you would like to talk to a midwife please contact us on 0800 0147 800 weekdays 9-5 pm
By Anonymous (not verified) on 1 Mar 2017 - 13:23
Good afternoon, I really cannot remember my last date for menstrual period, but I tested positive for home test on the 21st.of February. My last period was around the second to the last week in January, and I ovulate d around 4_7 of February. How old can it be?
By Midwife @Tommys on 3 Mar 2017 - 12:39
If you have a positive pregnancy test I would suggest that you arrange to see your doctor. Without accurate dates the best way to date the pregnancy is to do an early pregnancy scan. Your GP will be able to arrange this for you. Best wishes from Tommy's midwives.
By NAYELLE (not verified) on 28 Feb 2017 - 21:55
Hi.. I found out i was pregnant a week ago 20th feb 2017.... Just two days ago, i saw blood whilst taking a shower. I rushed to the hsp and was giving injection to stop the blood. It has stopped now but the gyn after doing the ultrasound said there was a pregnancy but not really formed. I'm soo scared and dont know what to do