The time for menstruation to return after a cesarean section depends on how the mother feeds, how long she breastfeeds, and how well her ovaries recover. Under normal circumstances, if the mother does not breastfeed, the ovarian function will return to normal in about 4-6 weeks after the cesarean section, and normal menstruation and ovulation will occur within 10 weeks at the latest. For exclusively breastfeeding mothers, the recovery of menstruation is around 18-20 weeks after delivery, and even some breastfeeding mothers do not resume menstruation throughout the entire period of breastfeeding. There are also some mothers with insufficient breast milk production or mixed breastfeeding whose menstrual recovery time may be earlier. So the time for menstruation to resume after a cesarean section depends on the circumstances. However, it should be noted that the fact that menstruation has not resumed does not mean that the ovaries are not ovulating. If you are having sex at this time, it is best to take correct contraceptive measures to avoid unwanted pregnancy.