Jump to What happens at the doctor's appointment? - Most aren't cancerous, and a doctor can remove them during an appointment. Other causes of vaginal bleeding after sex include: Friction during sex or not enough lubrication. Cervical ectropion (when the inner lining of the cervix pokes through the cervical opening and grows on the vaginal side of the cervix). There are many reasons why a woman may bleed after sex. The medical name for this is "postcoital bleeding". If you're concerned because you history and assess your symptoms. They can then advise you if any treatment is needed.