Morning sickness
Why nausea and vomiting happen in pregnancy, when they ease, what helps and when to call a doctor.
3 min read
First trimester
Week 3 of pregnancy
The egg meets a sperm and a new life begins: a single cell that keeps dividing as it travels to the womb.
Your baby this week
- Conception happens in the fallopian tube; from this moment the baby’s sex, eye colour and many other traits are set.
- The fertilised egg divides into 2, 4, 8 cells and more, forming a tiny ball of cells.
- This ball of cells, the blastocyst, travels for a few days towards the womb.
Your body this week
- You will not feel anything yet, and it is too early for a pregnancy test to show positive.
- Your body starts making more progesterone, which keeps the lining of the womb ready for the baby.
- Some women have light spotting as the blastocyst settles into the womb, at the end of this week or in week 4.
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Read more for this stage
Your first pregnancy appointments
When to see a doctor once you know you are pregnant, what happens at the first appointment and what the check-ups look like until the birth.
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Early signs of pregnancy
A missed period, tiredness, sore breasts and nausea: how to recognise the early signs, when to take a test and when to see a doctor.
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General information written by the mam.al editors. Every pregnancy is different and sizes are averages; it does not replace advice from your doctor or midwife. Sources include the NHS week-by-week guide to pregnancy. NHS. Contains public sector information licensed under the Open Government Licence v3.0.