(PCB) Bleeding after sex. Typically the result of abrasion of the cervix (which may be abnormal and you should have an examination and a PAP smear) or of trauma to the vagina. Sometimes due to a cervical polyp. PCB

A polyp of the canal of the cervix. A cause of bleeding after sex (postcoital bleeding). Sometimes accompanied by an endometrial polyp, which can cause infertility, and which should thus be looked for with a transvaginal ultrasound.

Inflammation of the cervix, usually because of infection. Sperm might or might not have trouble getting through the cervical mucus: this can be tested with a postcoital test. Occasionally cervicitis can mean that there is endometritis and salpingitis, in which case there will usually be pus present in the cervix. A cause of intermenstrual bleeding and postcoital bleeding. Clinically there might be contact bleeding when taking a PAP smear.

(IMB) Bleeding between periods that are otherwise regular. If it happens while on the oral contraceptive pill it's called breakthrough bleeding; if it happens over a few days before a period starts properly it's premenstrual spotting; if it happens after sex it's postcoital bleeding. These forms of IMB have different, usually important, causes. The formal term for it is metrorrhagia.