Hello, thanks for using health care magic It is likely that the swelling and pains are as a result of trauma during the sexual intercourse. Pains resulting form trauma usually begin during the intercourse and may worsen shortly after as the area becomes swollen and inflamed. Another possibility could be an infection but it is less likely since the pain started at the time of the encounter. You should avoid sex for a while and maintain good hygiene especially as u are on your menses. In such cases, pain killers such as paracetamol or ibuprofen are usually prescribed. Hope this helps you. Best regards Dr. Achuo