I am 17 and not sexually active and have never indulged in any kind of sexual contact. About 2 weeks ago I developed a pimple on my penis which healed up on its own within 4-5 days and in the end a solid white pus ball came out of it. Then I had another one which burst open and some blood came out of it. Then another one which had this white pus ball in it. And now I have the fourth pimple. They do not cause pain but do itch sometimes and are located on the underside of the penis and heal within 5 days. When the first pimple appeared at that time I was under stress due to my Mains upcoming examination. Please give me some suggestions as to what problem I could be having?