Mumsnet pregnancy calendar

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Week by week pregnancy calendar

Congratulations, you're pregnant. Our week-by week guide to your pregnancy will, we hope, tell you fascinating facts about what's happening to you and your growing baby.

From a bundle of cells to a fully formed baby, it's an extraordinary 40 weeks of development - and it's all hosted by you.

Embryo at week four40 week baby

But first, a few notes about using our week-by-week guide:

  • Use the slider above to see what to expect in each week of your pregnancy.
  • Not all babies develop at the same time and in the same way, so what we say may not always match your own experience. If you have any worries, ask your antenatal team or GP.
  • These guides will sometimes tell you about what can go wrong. Thankfully, it's rare for things to go wrong, especially after the 12th week, so please enjoy your pregnancy and don't worry.
  • We all know babies come in two flavours but, as most of you won't know what flavour you're getting, for clarity we'll refer to your baby as 'she'.

Your pregnancy is counted from the first day of your last period. Strange as it may seem, when the sperm meets the egg you're already counted as two weeks pregnant. So, when your pregnancy test is positive you'll be five or six weeks through your total of 40 without realising. This is good news as time can stand still when you're pregnant - especially in the home straight. Your baby, however, starts sprinting to the finish line as soon as conception occurs. 

Expecting baby number one (or two, or three...)? Why not join us at Bumpfest - our one-day event packed with talks, workshops and activities to prepare you for becoming a parent.

Our pregnancy calendar is written by Dr Luisa Dillner. She has five children and is head of research and development at the BMJ Group. She trained as a doctor in Bristol and gained her fellowship of the Royal College of Surgeons. She is a big fan of Mumsnet. She writes for The Guardian and other newspapers and magazines on health and relationships.


The Day by Day Pregnancy Book coverThe illustrations in our Pregnancy Calendar are taken from the bestselling book The Day-by-Day Pregnancy Book, £25, published by DK.

Disclaimer: The information in the pregnancy calendar is for general information and is not intended as a substitute for the medical advice of your own doctor or antenatal team. Not all babies develop at the same time and in the same way, so this week-by-week guide may not always match your own experience. If you have any worries, consult your antenatal team or GP.

Last updated: 19-Aug-2014 at 11:26 AM