Hello. I'm a 23 year old male who recently had unprotected sex with a friend. As far as she knows, she does not have an STD. However, a few days after sex, I noticed a small reddish section on the "rim" of my penis, on the right side. Additionally, some of the skin on the head of the penis near the red area is also more red than the rest of the head, and the skin appeared to be "shinier" than the rest. Although the discoloration has become less noticible, it is still there, both on the rim and the head. There generally isn't any pain, though it does hurt a little bit if I engage in repeated activities.
I also notice that it becomes more red after sexual activity or masturbation, and slowly returns to normal if I leave it alone for a while. For masturbation, the area is where I tend to rub the most. I'm worried that I may have herpes, as it does look similar to some photos I have seen. Any help would be greatly appreciated.