The manifestation of symptoms when menstruating can vary greatly from one woman to another due to her body type and genetic factors. If a woman does not have painful periods, but her menstrual cycle is regular and her menstrual flow is normal, this is a particularly normal physiological manifestation. This is because not all women have stomach pain when they have their period. Generally, they may experience soreness and discomfort in the lower abdomen when they have their period, and as long as there are no obvious symptoms of menstrual pain, there is no need to do any treatment. If a woman’s menstrual flow is abnormal, especially low, and the color is black, and there is no pain, it is not excluded that the abnormal phenomenon is caused by the lack of ovulation.