Pregnancy calendar

We've got all the information you need about your body, your emotions and your baby, week-by-week of your pregnancy.

Find out about the stages of your pregnancy

  • Weeks 1-12 infographic

    First trimester: weeks 1 to 12

    The first weeks of your pregnancy are a vital time as your pregnancy gets established. While you get used to being pregnant, your body is busy building a baby!

  • weeks 13 - 28 infographic

    Second trimester: weeks 13 to 28

    The second trimester is the middle three months of your pregnancy. You will start to look and feel pregnant. This is a time when lots of women tell the world they’re pregnant and begin to feel like the pregnancy is more ‘real’.

  • week 29-40  infographic

    Third trimester: weeks 29 to 40

    The end of your pregnancy is in sight. It won't be long until your baby arrives. Feelings at this stage of pregnancy tend to vary from tiredness and worry to excitement about the baby.

What is a trimester?

People often talk about pregnancy as being nine months long. In fact it’s usually slightly longer than this. Your pregnancy is measured from the first day of your last period rather than the day you actually conceived.

A pregnancy generally lasts around 40 weeks, and your dates are referred to in weeks because this is more accurate than talking in months.

Your pregnancy has three phases, called trimesters, and each trimester is about three months long.

Each trimester has its own mix of highs and lows, and you can find out what to expect in this pregnancy calendar. The information in the calendar may be helpful for the people close to you as well.

Read more

  • Pregnant woman looking anxious.

    Mental wellbeing

    Although it’s normal to have periods of worry and stress when you’re pregnant, some women have feelings that don’t go away and this can be a sign of something more serious.

  • Pregnant woman exercising on cross-trainer.

    Exercise and activity in pregnancy

    People may tell you that pregnancy is a good time to put your feet up. If your pregnancy is uncomplicated it is actually much healthier for you and your baby to exercise while pregnant.

  • Woman on treadmill at gym.

    Weight management in pregnancy

    Although you will be putting on weight in pregnancy as your baby grows, limiting the amount of extra weight gain in pregnancy will improve your health and your baby's, both now and in the future.

  • Woman in hospital bed being comforted by health professional.

    Pregnancy complications

    Sometimes things go wrong during pregnancy and you need extra care

  • Mother and newborn baby.

    Labour & birth

    Most women worry about how they will cope with the pain of labour and birth. You may worry too, especially if it is your first baby and you do not know what to expect.

  • Pregnant woman with sharp pain in her stomach.

    Is it serious? Pregnancy symptom checker

    In many cases the symptoms in this section will not lead to a serious complication and will be treated easily. Occasionally though they are signs of a more serious complaint.


1. NHS Choices [accessed 2 February 2015] “Your pregnancy week by week”

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Last reviewed on April 1st, 2014. Next review date April 1st, 2017.

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  • By Midwife @Tommys on 18 Jan 2017 - 10:17

    Hi please if you need to talk and don't have internet you can call us on 0800 0147 800
    Thank you
    Tommy's Midwives

  • By Anonymous (not verified) on 18 Jan 2017 - 05:52

    Please help nd I don't have email

  • By Anonymous (not verified) on 15 Jan 2017 - 21:18

    Hey there im 7 weeks pregnant and over the last few days ive gotten a bad itchy rash all over my legs and starting a bit on my arms is this normal during pregnancy? And what can I do to make it go? Im taking Elevit and wondering if that could be the reason?

  • By Midwife @Tommys on 16 Jan 2017 - 09:24

    Hi Maureen. Pregnancy can cause changes to your skin, some of these are deemed to be "physiological" or normal, and others can be a cause of concern. It is best to consult your GP/doctor/midwife as soon as possible with any rash that is sudden or unusual for you. Some rashes are specific to pregnancy, some are non- specific which can occur at any time in life and some is an itch, with no rash. You may be given treatment if necessary, but you certainly need to be reviewed before the type of treatment could be started. Sometimes it might be necessary for you to have a blood test too.
    Take care of yourself

  • By Anonymous (not verified) on 28 Dec 2016 - 08:15

    hey I'm new to this page I've had 3 .miscarriages in the past 2 years. I just found out that I was pregnant again. just praying everything goes well

  • By Midwife @Tommys on 5 Jan 2017 - 16:36

    Congratulations on your pregnancy and on finding our support pages. We hope you find the information helpful. We also hope that your pregnancy goes well. Please feel free to contact us should you need or want any advice or support. Best wishes x

  • By Midwife @Tommys on 15 Nov 2016 - 09:46

    You are correct, the calculation for your due date is taken from is from the first day of your last period. Hope that helps. If you have any more questions and want to talk to a Midwife you can call us on 0800 0147 800 or email us on

  • By Anonymous (not verified) on 14 Nov 2016 - 16:58

    How to calculate how many days I'm up from my last period?
    Is the calculation start from first day of the last period? OR calculation starts from the last day or end of the periods????

    Please clarify my confusion?????

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