If there is a small amount of bleeding, but no extensive endometrial stripping or increased menstrual flow, other factors should be considered. For example, to rule out the chances of pregnancy, if the month of unprotected intercourse, may also cause bleeding, but not cause extensive bleeding, so to rule out the first. For example, when there is endocrine hormone imbalance, estrogen, progesterone and even some androgens are on the high side, which may cause low menstrual flow, so this is to check the endocrine hormones when menstruation comes to exclude whether there is such a problem. If you have eaten some spicy and stimulating food, including cold food, and suddenly changed the environment, this may cause the chance of low menstrual flow. If it is more than the second day or the third day, still less, is suggestive of the existence of abnormalities. Need to go to the hospital registered gynecology first do a ultrasound to determine the thickness of the lining, you can take oral medication to promote menstruation. It is possible that such bleeding is not menstruation, but abnormal bleeding that needs to be ruled out.