About four days ago I noticed a bump on the lower part of my penis shaft. I have no idea what is, obviously. It was red for about 3 days and today I noticed a small white part on the top which led me to believe that it may be a pimple, but I don't know for sure. I does not itch but it does hurt when I touch it or when it rubs against my testicles. I am 16 years old, a virgin and circumcised. Does anybody know what this is and should I try to squeeze it? (its about the size of a BB) thank you.

It sounds like a pimple. Bumps of every size, shape, color, texture, and softness/hardness are extremely common in both men and women, anywhere on the body where there is moisture and close contact with other parts of the body, and usually closed in from air too (although people get skin conditions even in their smile creases and eyelids and so on). So I would leave it alone, and don't wear tight clothing.

Meanwhile it doesn't hurt to look on the internet at the pictures of various kinds of skin conditions caused by sexual contact, even though you aren't having any. Just start with a search on STD. Most of us know someone who caught something like herpes, which is the genital form of a very common virus like the one that causes cold sores on the lips, but which isn't curable and comes and goes for life. It helps to be armed with knowledge.