I am sexually active, and noticed that i have very tiny white bumps on my penis shaft. They will come at random and are in the form of one single bump. There is no clusters, and there very tiny with a white head or white top. When i pop them they have a small hard white ball that comes out and then they bleed. They do not form and eventually pop and ulcer and scab over like hepres on there own unless i physically pop them. They do not itch or burn, or hurt or have any feeling. I have maybe had about 5 of them. Any ideas about what this may be ??