The time of the first menstrual flow after delivery should be about the same as the usual menstrual time, normal is about 3-7 days: 1. If you are not breastfeeding after normal delivery, the menstrual flow is faster, usually 4-6 weeks after delivery will resume menstruation. 2. If the amount of menstrual blood is still not significantly reduced for more than 7 days, you need to go to the hospital gynecology clinic in time to do a gynecological ultrasound examination to see if there is poor endometrial repair, as well as a sex hormone six test to analyze the changes in hormone levels to see if there is an endocrine disorder, and how long can menstruation come after delivery and whether the duration is normal are issues that need to be taken seriously.