Pregnancy Month by Month

Pregnancy is divided into 3 trimesters. The word trimester means “3 months.” This can be confusing, because a normal pregnancy is 40 weeks, a bit longer than 9 months. The first trimester takes place from conception through week 14. The second trimester is from week 14 through week 28. And the third trimester is from week 28 through labor and delivery. Of course, delivery varies a lot, but it averages at week 40.

Pregnancy timing is measured using “gestational age.” Gestational age starts on the first day of your last menstrual period (LMP).