Vaginal bleeding after sex is common. Although it's often called "vaginal" bleeding, most benign bleeding in younger women comes from the cervix. However other parts of your genital and urinary systems can be involved.
Possible causes of vaginal bleeding after sex include:
If you're premenopausal and have infrequent episodes of vaginal bleeding after sex — and you've had normal results on routine Pap tests and sexually transmitted infection screenings — you don't need to see your doctor. For vaginal bleeding that worries you, make an appointment with your doctor. If you're at risk of or feel you have been exposed to a sexually transmitted infection, see your doctor for an evaluation.
If you're postmenopausal, vaginal bleeding at any time must be evaluated. See your doctor to be sure that the cause of your vaginal bleeding isn't something serious.