1st trimester

Search our pregnancy calendar for a detailed ‘week by week’ guide to you and your baby’s development.

Please note, for your personalised calendar you must be logged into the Club.

1st trimester

Pregnancy development in the 1st trimester

Week 1 & 2

Week 1 & 2

Pregnancy is calculated from the first day of your last period and lasts around 40 weeks. Find out what happens during week 1 and 2 of your pregnancy.

Week 3 & 4

Week 3 & 4

The first trimester is very important in your baby’s development. Find out what happens during week 3 and 4 of your pregnancy.

Week 5

Week 5

You’ve just missed a period and perhaps carried out a pregnancy test - and you’re expecting a baby! Find out what happens during week 5 of your pregnancy.

Week 6

Week 6

Despite how early it is, the foundations of all the major organs are already in place. Find out what happens during week 6 of your pregnancy.

Week 7

Week 7

You may be experiencing what people refer to as ‘morning’ sickness. Find out what happens during week 7 of your pregnancy.

Week 8

Week 8

Your baby will be about 3cm and weigh about 3g. Development continues rapidly. Find out what happens during week 8 of your pregnancy.

Week 9

Week 9

Your baby's brain is four times the size it was at 6 weeks. Find out what happens during week 9 of your pregnancy.

Week 10

Week 10

A little more pregnant every day. Your baby kicks and moves - though you can’t feel anything yet. Find out what happens during week 10 of your pregnancy.

Week 11

Week 11

It’s important to take extra care during pregnancy - and it may be time to book antenatal/parenting classes!

Week 12

Week 12

At the end of the first trimester keep fit with your usual exercise. Find out what happens during week 12 of your pregnancy.

Next stage in pregnancy development

14 weeks2nd trimester

The 2nd trimester is often the favourite time of pregnancy as morning sickness has usually stopped and your bump is not too big.

> Find out what's in store for your 2nd trimester

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Have you got a question?

If you want more advice, please ask a question or visit our forum.

Otherwise, please get in touch with the HiPP Baby Club.