It is rather common and nothing to be alarmed about. That being said you do need to get those feet in some stirrups for a look. Regardless of what it is it can be taken care of and addressed. It could be something simple as a polyp or a little more bothersome like a chlamydia infection. It could be a little tear from a fingernail or a little abrasion from all that friction. If it is chlamydia or gonorrhea you need antibiotics because left untreated could lead to infertility,
Hello,
maybe bleeding was due to rough intercourse. If it persists then I would suggest a visit to your family doctor or a gynecologist so he can estimate the factors.