I am 36 and recently had intercourse with a new partner who has a long penis. The sex was pleasurable and not painful, but afterwards there was blood on his penis and on the bed. This sort of thing has never happened to me before and I'm worried that it might be more serious.
You should be worried. Vaginal bleeding during or after intercourse, called postcoital bleeding, or at any time outside of menstruation, is something to be concerned about. While it could result from the man's penis striking a tender spot of the internal vaginal wall, it may also be associated with a risk of cervical cancer. In one study of 142 women referred to a colposcopy clinic because of postcoital bleeding, 27 (19 percent) had precancerous or cancerous cells identified, even though most had had a negative Pap test within the past three years. Another seven women had benign cervical polyps that were removed during colposcopy. Colposcopy is an exam in which the physician applies a vinegar solution to the cervix and vagina, then uses a special instrument called a colposcope (a large, electric microscope with a bright light on the end) to help identify abnormal tissue that may require further evaluation.
A similar study of 248 women with postcoital bleeding alone or postcoital bleeding plus an abnormal Pap test found a rate of cervical cancer of 3.6 percent in the first group and five percent in the second, with rates of precancerous cells of nine percent and 66.1 percent respectively.
So even if you've recently had a normal Pap test, I urge you to see your doctor immediately for another Pap test, and, possibly, colposcopy.