I'm 25 and uncircumsized... when I pull the skin back, on the head of my penis for the past couple years I've noticed this bump. Its not even visible under certain lights but other days its clearly visible, and when I run my thumb against and across the foreskin I can feel a very distinct bump... its very small but its kind of unsettling..

I'd have it checked out. If it causes you to worry, then have it looked at and get an answer - we have enough on our minds without having to worry about...