Why does menstruation suddenly stop after having sex during the menstrual period

Patient's question:

Patient Gender: Zhang Xiaoxia
Description of Symptoms: After having sex during menstruation, the period suddenly stops. What could be the reason? Is it possible that there are any inflammations? Could it lead to infertility? What other conditions might it cause?

Doctor's answer:

Hello! Intercourse during menstruation can easily lead to gynecological infections or cause heavy bleeding.