Question

what causes pregnancy? how long does it last in humans​

Answer 1

The average length of human gestation is 280 days, or 40 weeks, from the first day of the woman's last menstrual period. The medical term for the due date is estimated date of confinement (E D C). However, only about four per cent of women actually give birth on their E D C.

fertilization and plantation of the fertilized zygote and further

d-e-v-e-l-o-p-e-m-e-n-t of the baby causes pregnancy

Answer 2

In order for pregnancy to happen, sperm needs to meet up with an egg. Pregnancy officially starts when a fertilized egg implants in the lining of the uterus. It takes up to 2-3 weeks after sex for pregnancy to happen.