So a couple months ago I started noticing a few redish/tan spots on my pubic area, over time they got smaller but recently it seems to be spreading and getting bigger.

They don't itch, and they aren't raised bumps or anything. They only person I've ever had sex with is my girlfriend and she says she knows she doesn't have any stds.

Im just curious as to what this might be, and I'm kind of embarassed to go to the doctor.