It's unlikely that your bleeding is caused by cancer.

Have you had a pap smear and pelvic exam within the last year?

It's more likely that it's caused by something like cervicitis (an infection of the cervix, usually caused by an imbalance of bacteria - sometimes sparked by antibiotics for something else like a sinus infection) or perhaps a uterine or cervical polyp (which bleed easily when bumped or disturbed with vigorous sex, horseback riding or strenuous activity). But it could also be caused by an std, so be sure to have it checked out before it progresses.

Go see your doctor and let us know how it turns out.

Take care.

If it was just a small amount of bleeding that stopped after an hour or two, then it could just be that your sex was rougher/more vigorous, or that you used a different angle that caused more friction. I bleed a little bit almost every time me and my boyfriend have sex, and i've been active for three years. It just depends. If you are worried, talk to your doctor.

Daile