The main reason for this is that it is related to endocrine disorder, residue in the uterine cavity, pregnancy and other factors. 1. Endocrine disorder: After childbirth, because the hormones in the body of the mother have not yet returned to normal, it is easy to cause menstruation to appear more or less, irregular cycles and other symptoms. This situation is a normal phenomenon, generally do not need to worry too much, usually in the postpartum six months to a year, or after stopping breastfeeding, menstruation gradually return to normal. It is recommended to eat high protein food, such as boiled eggs, shrimp, etc., and to exercise according to the physical condition, and to combine work and rest. 2. Intrauterine residue: If the menstruation stops after one visit, it is necessary to consider whether the menstruation is caused by vaginal bleeding due to placental residue in the uterine cavity. At this time, it is recommended to go to the hospital for uterine cavity examination to avoid residual tissue in the uterine cavity; 3. Pregnancy: experiencing menstrual flow after childbirth indicates that the ovarian ovulation function has gradually recovered. In this case, if you have intercourse without using contraception, it is easy to get pregnant again. At this time, you can check whether you are pregnant through early pregnancy test or HCG test.