Aunt refers to menstruation, menstruation comes suddenly not, there may be abnormal bleeding is not menstruation, there may be a menorrhagia. 1. Abnormal vaginal bleeding: If it does not come to the normal time of menstruation, then it may be ovulation bleeding, usually less bleeding, will stop by itself. If it is accompanied by delayed menstruation, we should consider whether there are pregnancy-related diseases, such as preeclampsia or ectopic pregnancy. 2. Low menstrual flow: If the menstrual cycle is normal, it is possible that the low menstrual flow is caused by hormone levels or environmental factors, so you can consult a doctor in time and choose the appropriate treatment. Women should pay attention to keep warm during menstruation, in addition, pay attention to relax and maintain a good mood. If there is any discomfort, it is recommended to consult a specialist.