Is it a problem if I didn't know my period started during intercourse?

During intercourse, if one is unaware that menstruation has started, it is generally not a concern if the woman does not experience any physical discomfort. However, if discomfort occurs, it may be more serious and requires further evaluation and treatment at a hospital.

Menstruation refers to the cyclical shedding of the endometrium accompanied by bleeding due to the periodic changes in the ovaries. It is an important physiological phenomenon in women of reproductive age and typically follows a regular, self-limiting cycle. Under normal circumstances, sexual intercourse should be avoided during menstruation to prevent infections that could affect a woman's health. However, if intercourse takes place without knowing that menstruation has begun, it does not necessarily cause harm. If the woman experiences no discomfort afterward, it is usually harmless and does not affect health. If significant symptoms such as fever or abdominal pain occur after intercourse, an infection may be suspected, and medical evaluation—including physical examination and vaginal discharge tests—should be conducted at a hospital to determine the severity and receive appropriate treatment.

During menstruation, women should pay attention to weather changes and dress appropriately; maintain a healthy diet and avoid overeating; and ensure adequate rest while avoiding excessive fatigue.