Hi.
This is a gynecological question, so if you'd like a very detailed gynecological answer, I'd suggest you post in the Gynecology Expert Forum at
http://www.medhelp.org/forums/show/103
This is more common than you'd think. A large penis pops out unexpectedly, tearing the delicate skin on your labia. Ouch!
With rest, pain killers, warm water and loose clothes, you should heal fairly quickly; however, you might also want to call your gynecologist's office and speak to the nurse to get information about whether they can prescribe anything for you. Another option is to visit the Planned Parenthood or women's clinic in your area.
When having penis-vagina sex it's important that you're 1) sufficiently turned on and 2) sufficiently lubricated. The skin around your labia is very delicate and easily bruised or irritated. You also need to impress upon your partner that he needs to go slow and not try to initiate penis-vagina sex until you say you're ready. That's important. No p-v sex unitl you're ready! Don't fall into a bad habit now which will be difficult to change. Many women feel they "should" have p-v sex when their partner wants it, and this can be very harmful because it sets up a destructive pattern. Best of luck to you. Dr. J