Week by week of pregnancy + time calculation

Pregnancy usually lasts 280 days or 40 weeks, which conventionally starts from the first day of the last menstrual period. This period can be divided into three "trimesters" of pregnancy, in each of which specific events occur; The first trimester is from the first week of pregnancy to the end of week 13, the second trimester is from week 14 to the end of week 27, and the third trimester is from week 28 to the end of week 40, mostly at this time (slightly earlier or later) to childbirth and birth. The baby ends.