I was recently with a woman who i do not know what she had. We never had sex being that I could not get erect but she was on top of me with her pants off. It has been a week and i have no symptoms except for just last night i began having a slight pain in the inside tip of my penis. It goes away when i pee or ejaculate. But I was with someone last night and near the time of finishing we were interupted and unable to finish. It is a minor pain but I am just worried it is some sort of STI or it could be something else. Please help, I am very worried.