What Causes A Bump On The Glans Of Penis?

I have a small round bump on the glans and one on the underside. I saw the first one on glans over a week ago and the one on underside abotu 2 days ago. The one on glans in not moist, doesn't hurt or itch and it used to be flat and now is raised. I haven't been very hygenic lately and masturbaded more frequently than usual. What can this be?