Pregnancy Month 3

Overview of month 3

Month 3 spans roughly weeks 9 to 13 and completes the first trimester. The embryonic period ends and the developing baby becomes a fetus. For many people this is also the month of the first-trimester scan and the time they share their news.

Weeks in pregnancy month 3

Your baby in month 3

All the major organs have formed and begin to work. Fingernails start growing, bones begin to harden, and reflexes appear. By the end of the month, the baby is about 7 cm long and moves frequently, though you will not feel it yet.

Your body in month 3

Nausea and tiredness often begin to ease towards the end of month 3. A small bump may start to show, especially in a second pregnancy.

Care during month 3

First-trimester screening, including the nuchal translucency scan, is typically done between 11 weeks and 13 weeks 6 days. Cell-free DNA screening may be offered from about 10 weeks. Schedules vary between countries and providers; your own care team will tell you what applies to you.

Why pregnancy months are approximate

A 40-week pregnancy does not divide evenly into nine calendar months: each calendar month is about 4.3 weeks, so nine months is roughly 39 weeks, and the due date falls a week or so later. Different books and apps therefore group weeks into months slightly differently. This site uses the common grouping in which month 3 spans about weeks 9 to 13. When you talk to a healthcare professional, you will hear weeks and days — for example “10 weeks and 2 days” — because that is far more precise. To see exactly where you are, use the Pregnancy Week Calculator.