The menstruation usually proves that there is no pregnancy, but it should be the same as the usual menstruation, at the time when the menstruation is usually due, and the amount of menstruation is the same as the usual menstruation, and it clears normally when the menstruation clears. If the time of menstruation is wrong or the amount of menstruation is particularly small and there is dripping bleeding, it cannot be ruled out that the bleeding is caused by pre-eclampsia after pregnancy and is mistaken for menstruation. If the above symptoms occur, you should go to the hospital for a blood HCG test to rule out pregnancy and an ultrasound to check the condition of the uterine appendages and the lining of the uterus to see if the menstruation is caused by a gynecological disease.