The first stage of labor starts with regular and intense contractions. It ends when your cervix, the lower end of your uterus, is fully opened, to about 10 centimeters. On average, this stage lasts 12 to 19 hours. No two women are alike, and the length of early labor can vary a lot.
The second stage, when you push the baby out, lasts from 20 minutes to two hours. The placenta, or afterbirth, comes out in the third stage.