Girls are not allowed to have sex when they are menstruating. Although menstruation is a normal physiological phenomenon, resistance and immunity are down. In addition, due to the drop in hormone levels, it can also lead to emotional changes. If you have sex during menstruation, it will cause a lot of psychological pressure, and over time it is likely to produce resistance to sex, so you can’t have sex during menstruation. In addition, if you have sex during menstruation, it will cause sexual excitement and orgasm, which will change the hormone level in the body during sex, then it may cause a decrease in the amount of menstruation or lead to a completely clean menstruation, so you can’t have sex during menstruation. In addition, having sex during menstruation may also cause inflammation of the genitals, such as vaginitis, cervicitis, endometritis, so it must not have sex during menstruation.