The following signs may occur before menstruation: 1. Increased vaginal discharge, mainly due to the fact that the endometrial glands begin to secrete heavily before menstruation, leading to increased vaginal discharge. 2. Some people may also experience breast tenderness, often due to insufficient hormone secretion in the body. 3. The presence of fever, due to the increase in basal body temperature after ovulation, at around 37 degrees, can lead to a more fear of heat, indicating that it is possible to have a menstrual period in clinical terms.