My 17 year old son came to me last night saying he had a bump on his penis and was worried. Apparently it was not there before yesterday. Is it something he should be worried about?

Lumps and Bumps on the penis are very common and most do not have a serious cause. Have you actually seen this bump on your sons penis? Maybe you should look for yourself. Is it a spot? Or is it a bump under the skin? Also, is your son a virgin?
Once you know all of this, then ask the question again. You haven't really given enough information for advice.
Best of luck!