U. S. Sen. Hillary Rodham Clinton, D-NY, and, former President Bill Clinton, blow out the candles on a cake at Hillary Rodham Clinton's 59th birthday party at Tavern on the Green in New York, Thursday, Oct. 26, 2006.
The unborn baby spends around 38 weeks in the uterus, but the average length of pregnancy, or gestation, is counted at 40 weeks. Pregnancy is counted from the first day of the womanâs last period, not the date of conception which generally occurs two weeks later.
A normal, full-term pregnancy is 40 weeks, and can range from 37-42 weeks. Itâs divided into three trimesters. Each trimester lasts between 12 and 14 weeks, or about three months. Each trimester comes with its own specific hormonal and physiological changes.