Is vaginal bleeding after intercourse normal? I've been bleeding profusely afte intercourse (about 36 hours) with no pain. History of pcos, last pap (normal) 7 months ago, gave birth vaginally 19 months ago, family history of breast cancer

No it is not. I would advise you to go see a gynecologist and be examined and make sure there is no other cause for vaginal bleeding such as a benign or malignant lesion in the vagina or on the cervix.
The . The source of vaginal bleeding after sex is most commonly from the cervix - the part of the uterus that hangs into your vagina. It is most likely just cervical irritation from the friction of sex. As long as you are premenopausal (which you are), the bleeding is infrequent, and you have normal, regular pap smears, then you don't have to see your doctor for it. If you are postmenopausal, have bleeding that is heavy or every time you have sex, or if you have had abnormal paps smears in the past, you should see your doctor to rule out more serious causes such as cervical cancer.