Under normal circumstances, primiparous women usually begin to enter labor after 36 weeks. It is possible that the fetus will not enter the pelvis until after labor. 1. Primigravida: Under normal circumstances, primigravida women usually have their fetus in labor two weeks before delivery. Most primigravid women have their fetus in labor after 36 weeks, but the time of labor varies from one woman to another. 2. PMS women: PMS women have given birth to babies, the pelvis is more loose, after labor, it is possible that with the dilatation of the cervix, the baby will enter the pelvis while giving birth. After the fetus into the pelvis, pregnant women will feel abdominal fullness than before relief, may feel the small abdominal swelling, and even accompanied by frequent urination. Pregnant women should pay attention to regular obstetric checkups during pregnancy, especially in the late stage of pregnancy, if at any time there is abdominal pain or vaginal redness, etc., it is important to seek medical attention as soon as possible.