Pregnancy Calendar - three trimesters It can be difficult to
Pregnancy Calendar - three trimesters
It can be difficult to know exactly when a woman falls pregnant, and the start date of a pregnancy calendar is usually estimated. A pregnancy is divided into trimesters: the first trimester is from week 1 to the end of week 12, the second trimester is from week 13 to the end of week 26, and the third trimester is from week 27 to the end of the pregnancy.