The following signs may occur before menstruation: First, some people may experience localized breast tenderness, mainly due to high estrogen secretion and low progesterone secretion in the body. Secondly, before menstruation, there is an increase in vaginal discharge, mainly because the endometrial glands secrete a lot before menstruation, which leads to an increase in leucorrhea, but the increase in leucorrhea does not change in nature, the leucorrhea is still milky white and has no odor or only a faint fishy smell. Third, before menstruation, if the basal body temperature is monitored, the basal body temperature will drop, and when the basal body temperature drops for about 24 hours, menstruation will occur. These are the signs and symptoms that appear in the clinic to come to menstruation, if the above signs and symptoms appear, it is recommended to prepare for menstruation.