first trimester
The first trimester begins on the first day of your last period and lasts until the end of week 12. This means that by the time you know for sure you’re pregnant, you might already be five or six weeks pregnant! A lot happens during these first three months.
second trimester
The second trimester of your pregnancy lasts from week 13 to 28, or months 4, 5, and 6. It’s the middle phase of pregnancy, when you may start to see your “baby bump” and feel your baby move for the first time.
Third Trimester
The third trimester of your pregnancy is from week 29 to week 40 – months seven, eight and nine. Feelings at this stage of pregnancy tend to go from tiredness and worry to excitement about the baby. Your baby continues to grow, and as the third trimester progresses they’ll have a better chance if they’re born early.