I have begun having sex with my girlfriend, and this is the first time for both of us. Its been about two months since we first did, and we have unprotected sex once. The last week, I have noticed small red bumps on my penis. They have no black or white heads, they look similar to razor burn. They are on the lower half of the shaft. I am worried obviously that these may be an std but I would love some advice on what to do.