What Causes Tiny Bumps On The Glans Of Penis?

Hi, I have noticed some tiny dots on the underside rim of my glans penis. These are almost unnoticeable but when i get an erection they become more prominent or if i pull the skin to expose them. Some on the very edge of the rim at the top look like tiny red pimples? They are also more on the left side of the rim and less on the right hand side. What could these be?

I went to a GUM centre and they said its nothing to worry about, its normal for everyone to have these but i wanted to get a second opinion???