Labor has 3 stages. The first one is active labor, which is the longest. Second is the pushing phase/delivery. Third is the shortest - the delivery of the placenta. The cervix must be completely opened (dilated) and fully thinned out (effaced) to allow for the baby to be delivered. Active labor begins when the cervix begins the process of thinning and opening. The uterus begins contracting. At this time women may feel pressure, back or lower abdominal pain and even a tightening up of the belly. When contractions are over the uterus relaxes and the belly softens. Every time a contraction comes, the cervix opens up and also pushes the baby down. They will become more intense, last longer, and come closer and closer together until the baby is born. If your contractions become consistent and if you think your water has broken - which means the fluid-filled amniotic sac that protects the baby ruptures - you should contact your physician. If you have had a cesarean before, but are interested in a vaginal birth, ask Dr. Hill about vaginal birth after C-section.