Uterine Fibroids — This is another type of abnormal growth that can occur in the uterus and cause bleeding. Vaginal Trauma — Any kind of trauma to the cervix or vagina can result in bleeding. Cervical Dysplasia — This is a condition where precancerous cells may be lining the uterus. The resulting infection can cause itching which may cause bleeding or tearing of the vagina. In this case, blood can be a bright red color at first, then may turn into a darker red as it dries. See your doctor to rule out cervical cancer , endometrial cancer , and other issues. Signs and Symptoms of Cervical Cancer. All of these symptoms with vaginal bleeding can indicate a possible life threatening problem and you should be examined by a doctor right away. Causes The following conditions and diseases can cause vaginal bleeding after sex: If you have a history of cancer in your family and experience bleeding after sex, it is especially important for you to get checked by your doctor as soon as possible. In the case of abuse or assault, the bleeding would typically be from vaginal dryness or a lack of lubrication in the vagina. Vaginal Yeast Infection — A vaginal yeast infection occurs when yeast that is normally found in the vagina begins to overgrow. Menstruation — If you experience bleeding after sex around the time of your period, this may be the first cause to look at. Removing cervical polyps or treating cervical infections should also clear up post-sex bleeding, if either was the cause. In addition, menstrual periods can be affected by many things, including medications, strenuous exercise, certain diet changes and even stress. For some women, after their first sexual experience, the bleeding can continue for up to one day. You can also wait a bit longer after your period ends to start having sex again, if it seems like regular uterine bleeding at the tail end of menstruation is the culprit.