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.
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.
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.
- See all our pregnancy advice pages
- Due date calculator
- Chat about your pregnancy
- Join an online antenatal club
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.