What Causes Growth Of Extra Skin Under The Foreskin?

Underneath my foreskin, just below the head I have a ring of extra skin going around the penis. At first I thought it was just a spot of some kind so picked it and it did bleed a little (therefore not a spot). It doesn't really do any harm (unless picked - which I wont be doing again). I have only ever had sex once, but that was unprotected sex. I am just a little worried and would like an opinion on this.