Every now and then I bleed after sex. I heard that if you rarely bleed after sex it can be a sign of vaginal or cervical cancer?

Bleeding with sex. Bleeding after sexual intercourse, is a sign of cervical cancer; however, cervical cancer in your age group is extremely rare. It is doubtful that you have cervical cancer because if your age, but you need to see your gynecologist.
Yes. Best to have it checked by your gyn. Bleeding after intercourse may be a sign of gyn cancer.