light to medium bleeding after sex is usually due to a normal increase in the vascularity of the cervix during pregnancy. Vaginal bleeding , especially early during the first trimester, can be a sign of implantation , or it could be the result of natural changes to your cervix. bleeding after sex during pregnancy isnt uncommon, and there are several causes that are nothing to worry about. Pregnancy can cause changes to the cervix, and this may sometimes cause bleeding after sex, for example. During the first 12 weeks of pregnancy, vaginal bleeding can be a sign of miscarriage or ectopic pregnancy. However, many women who bleed at this stage of pregnancy go on to have normal and successful. vaginal bleeding during sex can be caused by many of the same things that can cause bleeding after sex. These include infection, vaginal trauma due to dryness, cervical polyps, menopause, and cancer. However, there are some other conditions that can cause bleeding during sex specifically. Bleeding during pregnancy is common, especially during the first trimester, and usually its no cause for alarm. But because bleeding can sometimes be a sign of something serious, its important to. sex doesnt cause preterm labour in a typical pregnancy, but if you are at risk of preterm labour, your doctor will recommend that you avoid sex. Less often, bleeding after sex during pregnancy can be a sign of something more serious. vaginal bleeding during pregnancy is any discharge of blood from the vagina. It can happen any time from conception (when the egg is fertilized) to the end of pregnancy. Some women have vaginal bleeding during their first 20 weeks of pregnancy. Vaginal bleeding after sex can be scary if youre pregnant, but it probably isnt a cause for concern. Your cervix may bleed more easily during pregnancy because extra blood vessels are. By contrast, studies say that anywhere from 46 percent to 63 percent of postmenopausal women will experience dryness, itching, tenderness, spotting, or bleeding during or after sex due to hormonal changes that affect the elasticity of vaginal tissues. But in most cases, spotting and light bleeding are just a normal part of early pregnancy.