The unborn baby during pregnancy spends about 38 weeks in the womb. However, the average length of normal pregnancy (gestation period) is 42 weeks. The length of pregnancy is normally counted from the start of the woman’s last menstrual period, and not usually the date of conception as much as we know that normally the conception occurs two weeks later.
A full-term pregnancy that is considered to be normal is about 40 weeks and or may vary in individuals or conditions from 37 to 42 weeks. Pregnancy is also divided into three trimesters. Each trimester takes about 12 and 14 weeks or an average of about 3 months.