Hello, I'm 16 and have just noticed a small bump on the side of my penis. Its quite small, it doesn't hurt and feels slightly hard and when I slowly start to squeeze it, it slightly hurts. I have got a girlfriend and within the last month we have had sexual intercourse but the last time the condom split and I pulled out immediately, although on other occasions for some reason I can't ejaculate with her, when I'm alone masturbating it is fine. I feel like it is a lymphocyte from quick research but I'm not quite sure. I'm slightly confident it is not an STI, any help or advice would be greatly appreciate as that I'm completely terrified at this point.