Hi everyone, your help would be appreciated. I'm a 17 year old male, who has never had sexual intercourse. I recently got involved in a long distance relationship with a great girl. Whenever we see each other, we often engage in oral sex. I do not think that I'm ready for intercourse, and my girlfriend is totally fine with that. Before she began dating me, she was quite promiscuous and has had many sex partners.
Recently I noticed a red bump on the shaft of my penis. It has gone down greatly in size over the past week, but it is still visible. I am worried that this is some sort of STD, since there may have been some unprotected penis/vaginal contact during one of our intimate moments. Or it may just be a pimple, but I find that to be a bit odd.
Before this bump appeared, I went to my doctor because I was having problems getting an erection. He ran a blood test, and when the results came back, I was told that I was "perfectly fine." The erection problem is solved now (I believe it was stress) but would sexually transmitted diseases be checked in a blood test? Am I at risk?
Again, any help would be greatly appreciated.