A pregnant woman.

Pregnant zebra

Pregnancy is when a female mammal has an unborn baby inside her. During pregnancy, a female is called "pregnant". A human pregnancy is about 38 weeks long, from conception to childbirth. Usually the mother has one baby at a time. Sometimes the mother has two babies at one time. Two babies are called twins. The mother can have three or more babies at one time. This does not happen very often in humans.