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weeks pregnant

4 weeks pregnant - all you need to know

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.

4 weeks infographic.

Tommy’s midwives are here to support you by telling you everything you need to know about week 4 of pregnancy: advice on common pregnancy symptoms, practical actions, such as the ‘booking’ appointment and what’s happening with your baby.

Before week 4

Congratulations on your exciting news! If your periods are usually regular, conception is likely to happen in the middle of weeks one to four. You are very unlikely to know you're pregnant at this stage.

It may sound odd but pregnancies are measured from the first day of your last period rather than the day you actually conceived your baby. This is because it's not always easy to be sure of the exact date you became pregnant.

“I spent the entire week my period was due running to the loo, just to double check I didn’t have my period. My boobs felt tender - but that can be a sign of PMT too. I took an early test in the end and couldn’t believe it when it showed positive.” Ayida, mum of one

Although a fertilised egg may have implanted in your womb just two weeks ago, if the first day of your last period was four weeks ago, you are officially four weeks pregnant! This may seem odd if you think you can definitely date the pregnancy more recently.

Get weekly updates on your baby's development from our expert midwives straight to your inbox.

What does my baby look like?

The tiny person inside you is the size of a poppy seed. A little dot, measuring about 2mm.

The baby may be miniscule but big things are happening! The fertilised egg has snuggled into the side of your womb. It divides into layers of cells that will eventually become different parts of your baby’s body.

Your baby’s nervous system and heart are developing. Amazingly your tiny dot already has some of its own blood vessels and blood is starting to circulate. A string of these blood vessels connects you to your baby. This will eventually become the umbilical cord.

Right now, your poppy seed is known as an embryo. They get their energy and nourishment from a yolk sac (until the placenta takes over in a few weeks). Your baby is surrounded by amniotic fluid within the amniotic sac, providing a comfy cushion for them throughout your pregnancy.

Your symptoms - what happens in week 4

Early symptoms of pregnancy

Bleeding or spotting

You might notice some very light bleeding, or ‘spotting’, known as implantation bleeding. This can be caused by your little seed burrowing into the lining of your womb. It often happens around the time your period would have been due and is relatively common.

You may also have some period-like cramping in these early weeks.

If you notice any bleeding at any stage of your pregnancy, though, it's important to get it checked out by your doctor or midwife.

Sore boobs

This week, a surge in progesterone can start to make your boobs feel tender, heavy and sore - a bit like how they might feel before your period.

Remarkably, these are pregnancy hormones already preparing your body to produce milk. This tenderness usually eases off by the end of the first trimester.

Find out how to deal with first trimester pregnancy complaints or read more early pregnancy symptoms here.

Things to do in week 4

Smoking and alcohol in pregnancy

It’s time to quit cigarettes and alcohol. Both can be harmful to your growing baby because the toxins pass through the placenta.

Here’s our guide to avoiding alcohol during pregnancy.

Find out more about the effects of smoking in pregnancy.

And if you’re still struggling to stop smoking, these ten steps towards quitting could help.

If you use street or recreational drugs, stop or ask your doctor for advice on stopping safely.


Sexually transmitted infections (STIs) such as chlamydia, gonorrhoea, syphilis and genital herpes can affect your baby's health during pregnancy or birth.

If you think you or your partner might have an STI, go for a check-up as soon as you can. Your doctor or midwife can tell you where you can find your nearest sexual health clinic.

Don't worry, nobody will judge you and it's important to be checked as soon as possible.

Continue (or start) taking these supplements

There are two vitamins that are very important in pregnancy and that you can take as supplements: Folic acid and vitamin D.

Folic acid is naturally present in leafy vegetables, fruits and berries, beans and wholegrain products - but keep taking folic acid supplements too, until at least week 12 because you can't get enough through food alone to build up the level of folic acid that your baby needs.

Folic acid helps in the formation of your baby's nervous system and reduces the risk of spina bifida, which is where the baby's spine doesn't close up properly.

You should take:

  • 10 micrograms of vitamin D each day throughout your pregnancy and if you breastfeed
  • 400 micrograms of folic acid each day – you should take this from before you are pregnant until you are 12 weeks pregnant

Find out more about important supplements in pregnancy.

Tell the GP you are pregnant

Once you know you’re pregnant, make an appointment to see your doctor or a midwife to get any advice you need and to be booked in for your pregnancy care appointmentspregnancy care appointments. If you make a GP appointment, they will set you up for midwife appointments or you can call the maternity unit in the local hospital and refer yourself that way.

However you book it, your first appointment with the midwife will not take place until after week 8, the ‘booking’ appointment. This can make it an anxious time but reading through these dos and donts of pregnancy may help.

This is an important time to talk about any health issues you have to make sure your pregnancy goes well. It is very important to tell your doctor about any medication you may be on, especially long-term medicines for conditions, such as asthma, epilepsy, mental health conditions, diabetes, hormone therapy, heart problems and so on. Your doctor can make sure you are on the safest medication for you and baby.

It is very important that you do not stop taking medication without talking to your GP or specialist

Find out what questions you'll be asked at the booking appointment.

If you have an existing mental health problem

If you have a pre-existing mental health condition and take medication, tell your doctor and the person who prescribed the medication that you’re pregnant as soon as possible.

They will talk to you about whether your medication is safe in pregnancy or whether you should consider a different treatment.

Find out more about your mental wellbeing in pregnancy.

What are my chances of miscarrying?

It’s a sad thing to think about, but up to one in five pregnancies will end in miscarriage in the first three months.

If you do have light bleeding, spotting or stomach pains, this doesn't mean you are going to miscarry. However, you should always speak to your doctor or midwife and ask for advice.

Find out the other symptoms you should contact your midwife about.


1. NHS Choices.You and your baby at 0–8 weeks pregnant, NHS Choices: (Page last reviewed: 28/02/2017 Next review due: 28/02/2020)

2. NHS Choices. Vaginal bleeding in pregnancy (Page last reviewed: 26/01/2018  Next review due: 26/01/2021)

5. NHS Choices. Signs and symptoms of pregnancy (Page last reviewed: 06/10/2016 ;Next review due: 06/10/2019)

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    Last reviewed on June 22nd, 2018. Next review date June 22nd, 2021.

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    Please note that these comments are monitored but not answered by Tommy’s. Please call your GP or maternity unit if you have concerns about your health or your baby’s health.
    • By Ashley (not verified) on 24 Jun 2020 - 20:52

      I am 6 wk 3 days and I’ve been spotting since last night is this normal

    • By Xoliswa Lerato (not verified) on 23 Jun 2020 - 14:03

      Hi I had missed my period on 17 may but I never missed period like that I used to be in period like 5 or 6 days please i need your help I don't know if I'm pregnant or not and I'm always tired and thirsty and back pain please can you tell me is it possible that I'm pregnant or not

    • By Chery l (not verified) on 13 Jun 2020 - 04:33

      Hi, can anybody help me with my problem? Last March 2020 I had smectopic pregnancy..And we tried again after 3 months, and I just found out the other day that I'm pregnant again..Can someone give me an advice what to do please??? I'm scared that it might happen again for the ectopic.. Thank you so much.

    • By Kristie (not verified) on 12 Jun 2020 - 22:48

      Hi .. I last had my period on the 17/05/20 and I’m two days late .. I’ve been having on and off nausea , experiencing lower abdominal pains all the around to my lower part of my tummy .. want to know if I’m pregnant and when should I take a home pregnancy test for a positive result

    • By Kristie (not verified) on 12 Jun 2020 - 22:43

      I’ve been having consistent nausea like I want to vomit , I last had my period on 17/05/20 .. and I’m two days late ,been having abdominal pains no implantation bleeding but cervical mucus for the past week now , not sure when to do a pregnancy test to get a positive result .. advice please

    • By N (not verified) on 4 Jun 2020 - 20:25

      Just found out i am pregnant (3weeks post conception). I took a course of trimethoprim antibiotics for a UTI before i knew. I would be around 2weeks post conception when i took them. I need advice urgently as what ive read on the internet its not pregnancy safe especially in the 1st trimester. Please help, thanks.

    • By Beatrice (not verified) on 3 Jun 2020 - 20:51

      Hi my pregnancy is 4weeks old,and am feeling pain under my stomach,my body is weak and I am weeing fast with discomfort and am feeling to vomit with fever

    • By Winifred ani (not verified) on 3 Jun 2020 - 14:33

      hi,I had my last period on the 11 may 2020 my cycle is 21 or 22 days and I never miss my period when I calculated it today I am 4weeks and 3days and I just spotted blood could I be pregnant..plz help me ..thanks

    • By Ejiro (not verified) on 25 May 2020 - 13:16

      I was my last.period on the 24 of April but up till now have not seen my period

    • By Unknown (not verified) on 19 May 2020 - 05:36

      I just had a kid almost 10 months ago. Today I found out I was prego again but I have no idea how far along I am
      Bc I Havnt really had symptoms and my period has been random since I had my first kid. But the last time I had my period was a while ago... could I be 2 months pregnant?

    • By Jeff (not verified) on 12 May 2020 - 18:26

      We are newly married and trying to have our first child. My wife had her period on April 13th 2020. We had sex on April 26th 2020 so that we can time everything and she took a pregnancy test on May 10 and tested positive. Can this be accurate and can it happen that quickly.

    • By Jeanette (not verified) on 27 Apr 2020 - 14:51

      Hi I had a miscarriage on the 26th of march 2020 and on the 21st of April 2020 I found out that I am 1-2 weeks pregnant. The problem is today I had something like period pains n now I'm bleeding, does it mean I miscarried again please help

    • By Duke (not verified) on 11 Apr 2020 - 12:24

      I tested positive to d home pregnancy test... ND at week 4 I HV my period again... Though it was only normal at day 1 and other days were just drops and little clots... Pls am I still pregnant?

    • By am Roselyne (not verified) on 4 Jun 2020 - 05:21

      I am 4 weeks pregnant now but I have bleeded for a day now.... Am I still pregnant?
      Kindly help me..... I want to keep the baby yet I had lost another in stillbirth

    • By Jakyra Hedrick (not verified) on 4 Apr 2020 - 13:41

      So I’m 3-4 weeks pregnant and I was spotting and I went to the doctor they said I was dehydrated and need to drink more water but I’m scared and I want to know could it be the uti pills

    • By Malebo (not verified) on 3 Apr 2020 - 13:39

      I'm 4 weeks pregnant, I have cramps and pains on my legs arms, waist ,stomach and back pain and headaches.My stomach is making noise like when u r hungry I'm scared I may miscarry

    • By Eroubome joy (not verified) on 23 Mar 2020 - 15:19

      My period is 3 day late

    • By Tasha (not verified) on 10 Mar 2020 - 01:13

      Hi last period on 2/5/20 always 28 day cycle alway normal now tts 3/9/20 6 days past my expected period just see light pink spott

    • By Fiona ebi (not verified) on 2 Apr 2020 - 07:07

      You might be pregnant dear, do a home pregnancy test to be sure.

    • By Stiffie (not verified) on 6 Apr 2020 - 05:08

      Light pink spotting is usually what they call implantation bleeding: it means you’re fertilized egg is attaching itself to your womb!

    • By Dayana (not verified) on 24 Feb 2020 - 11:04

      Kindly anybody share the exact symptoms on your nearest periods dates and early pregnancy symptoms...will it be same...I'm trying for a baby but I have all usual pre-menus symptoms ...

    • By Anonymous (not verified) on 8 Feb 2020 - 01:01

      I was suppose to get my period February 1st and it never came so decided to take a pregnancy test and it came back positive yay but 5 days after I realized I was spotting but it was only for a day. Is that normal or should I go get it checked out?

    • By Boatemaa patience (not verified) on 24 Feb 2020 - 12:50

      I have my last period on the 1/23/2020 and on February 16 seen bleeding coming and stop by three days and feeling like I'm pregnant

    • By Mary (not verified) on 2 Mar 2020 - 01:06

      I missed my period i checked it was positive but I have untreated infection can I insert antifungal drug instructed by my doctor

    • By Ang (not verified) on 16 Mar 2020 - 03:17

      I'd recommend getting it checked out. On January 29th i started lightly spotting & feb 1st it got worse; Those 2 days were hospital visits with a blood test. The 29th the doctor wasnt able to tell yet/ the 1st he said sorry because it was noticeable in my blood that i had had a miscarriage. But thats ok....
      sad but I guess I got pregnant immediately after and now Im waiting a few weeks until my first ultrasound to see the proper date! Super exciting. I almost didn't go in, thought I was spotting... checkups are important. & no you didn't do anything wrong if it were a miscarriage, apparently it is a common thing. I'm hopeful though im nervous & scared because it's happened, im glad it was early on.. I was probably just 2 weeks.

    • By Ann (not verified) on 4 Feb 2020 - 03:44

      My last period was on 24 to 29 December, as at now I havnt seen my period I took a pregnancy test and its positive, this morning I saw some slimy discharge and then some light bleeding on my bed what could be the reason cux am worried

    • By Mc (not verified) on 3 Apr 2020 - 14:58

      I have small bleeding in 6 week pregnancy,what is the course

    • By tolulopeabimbol... (not verified) on 16 Jan 2020 - 08:04

      I am bleeding in my 4th week of pregnancy and am feeling pains what is about and what can I do

    • By Helen (not verified) on 12 Jan 2020 - 15:35

      l had 3 miscarriage then ectopic pregnancy which my left tube was removed all like 3years ago, later tried to be pregnant but not coming,hsg test shows blockage of the right tube that remains so no major hope until now that l just felt my breast is painful, missed period and pregnancy test positive,but very worried so as not to experience what happened in the past

    • By Mpho (not verified) on 4 Apr 2020 - 20:31

      Hi Helen,how is it going.

    • By Ks (not verified) on 20 Dec 2019 - 16:13

      I have confirmed implantation bleeding by my midwife which is brown but it smells odd is this normal? Please help

    • By m (not verified) on 17 Jan 2020 - 10:44

      when did you start this bleeding before/after your period was due?

    • By Stephanie (not verified) on 18 Dec 2019 - 11:29

      Hi, I have just found out I’m 4-5 weeks pregnant, I was prescribed metformin 6 months ago to help with PCOS, but stopped taking it 2 months ago as I found it wasn’t helping me, however I was told to keep taking it even if I did conceive. My question is should I start taking it again now I am pregnant?

    • By Natalie (not verified) on 16 Dec 2019 - 14:54

      I haven't had my periods since last month could I be pregnant

    • By Anonymous (not verified) on 20 Nov 2019 - 21:45

      Hi On the 27th of September I went to the doctor to take my 1st depo provera short and the next day my period begin sinces then I haven't seen my period could I be pregnant?

    • By Julia (not verified) on 14 Nov 2019 - 15:17

      Hi i did home pregnancy test and the result says i concived more than 3 weeks ago 5+weeks and my last period was on 14 September so i want to know when did i actually convinced?

    • By Midwife @Tommys on 19 Nov 2019 - 12:17

      Hi Julia,
      If you use our pregnancy calculator, in the link below, you can enter your last period date and your average length of cycle, it will then calculate your due date, how many weeks you are currently and will then help you to work backwards to work out roughly when you conceived. Tommy's Midwife

    • By Tumi (not verified) on 24 Oct 2019 - 10:38

      Hi there plz help I'm Tumi 28 last years October i had a miscarriage i was 3 months pregnant and didn't go for womb scrub now I'm pregnant scared what is might happen to my baby

    • By Nosiphowe (not verified) on 14 Oct 2019 - 18:34

      I have been having unprotected sex for the past 2 months .then this month I missed my periods due date by 5 days then on the 6th day I experienced heavy bleeding the. The blood got lighter and clotting .could be possible that I was experiencing a miscarrage

    • By Oke adewumi (not verified) on 30 Jan 2020 - 21:30

      Am scared

    • By Faheedat (not verified) on 1 Mar 2020 - 13:02

      Am bleeding

    • By Florence Susan scott (not verified) on 1 Oct 2019 - 20:28

      I really need to know been having some pains in my abdomen
      And I have Missed my period for one month
      Do you think it a sign of pregnancy

    • By J Salmond (not verified) on 15 Nov 2019 - 20:24

      Please see a GP. Sounds like you are pregnant. Good luck xx

    • By Grace (not verified) on 22 Sep 2019 - 13:11

      Hi. I just want to know if i had sex on august 24 and was pregnant when I had my OB check up on September 20, how many weeks is my baby?

    • By Natalie (not verified) on 2 Aug 2019 - 13:14

      Hi I've recently had a very light bleed that lasted 2 days but only when I wiped then I started with bad headache and light headed lower tummy cramps some lake yellowish or white discharge tired but I'm not due on till between 14th and 17th August could this be a sigh of pregnancy or is it to early thanks you for reading be happy for some one to comment as I don't no what's happening with my body and symptoms

    • By Lucy (not verified) on 25 Jul 2019 - 16:34

      Hi..i was suppose to have my period on the 7th till 10 july 2019..but now its the 25th i still ddnt get my i pregnant?

    • By Zain (not verified) on 25 Aug 2019 - 19:12

      Hi, you can have a pregnancy test at ur home. If u r not having the period this month, you have a chance of becoming pregnant. Don't think too much and have a check up at home or hospital. Thank you

    • By Caz (not verified) on 23 Jul 2019 - 16:14

      I had a miscarriage in 2018 and I've now found out that I'm pregnant again- I went to see a private consultant to have a internal scan as I was bleeding a lot and I was scared I was losing the baby. All is well I'm 5/6 weeks so really happy. The consultant put me on progesterone pessaries for 4 weeks to stop the bleeding, I'm concerned as I've read that it mask/delay a miscarriage- I don't know what to do .

    • By adeela (not verified) on 31 Jul 2019 - 01:59

      Hi there
      I just want to tell you relax
      What's going on will not change if you stressed
      I've had two miscarriages then a healthy baby and then again two miscarriages in Oct 2018 and Jan 2019
      Now I just did HPT and it's positive
      Hoping for the best
      I'm having abdominal cramps
      Going to visit a gynecologist soon
      Fingers crossed

    • By Louise (not verified) on 17 Aug 2019 - 20:58

      Hi I found out I was pregnant on 8th August which test said 2-3 weeks and I was bleeding was at d hospital and scan showed sac but nothing in it as doctor said I was too early or may be losing I wanted to ask was any one had same and had ok results pleas I am now 4 weeks and still bleeding heavy thank you .

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