Lower abdominal pain after sex. how to prevent this?

Depends on cause.: I am assuming that u e a woman but don't know for sure. It sounds like this is deep (vice superficial pain) have u had prior surgery (adhesions), ovarian cysts, endometriosis, hx of uterine fibroids or pelvic inflammatory disease, is your uterus tilted toward the back ? There are many possible causes. Please see your gynecologist to evaluate for cause. Often correctable causes can be identified.