I had sex with a college girl two and a half years ago. After three rounds I ran out of condoms, I was drunk. So, I made the mistake of not using one for the next round. The next day I realized exactly what I did. However, I was not cut on the penis, and did not have any open sores on my penis. Could HIV still have been transmitted to me if she were positive?
You do not have to have cuts or sores on your penis to get HIV infected when having insertive anal of vaginal sex without condoms. HIV can be transmitted when coming into contact with the mucous membranes that line the inside of your body. The mucous membranes that are likely to be exposed during sexual intercourse are the lining of the vagina, rectum, or in your specific case, the urethra (the tube you pee out of). Certain types of cells may essentially transport HIV from the surface of these mucous membranes to the white blood cells of a person's body where it replicates. Cuts or sores may provide HIV similar access, and possibly increase the risk of infection. HIV cannot be transmitted through intact skin.
Remember: your partner needs to be infected for transmission to be possible and transmission doesn't always occur when having sexual contact with an infected person.