Painful intercourse is also a common symptom of endometriosis...which can only be definitively diagnosed by a surgical procedure...diagnostic laporoscopy. Particularly if you have any pain or problems associated with your menstrual cycle...cramps, heavy bleeding, clotting, fatigue, etc....you should consider this as a possibility. Contact the Endometriosis Association for further information. The painful intercourse can occur anytime during the month...as the cul-de-sac is a common site for endometrial implants.