Skin rash but not itchy... =/?

I have a skin rash (so i think it is...) on my chest, chin, and forehead... on my chest they are lil red bumps but don't itch and on my chin and forehead they just look like tiny pimples... (it's rare that they itch)... I already made a doctors appt but its in 3 days and I'm just concerned... some people say its probably cause of the heat but I've never had a heat rash or any type of rash, not that I could remember... Well if any of you know about this should i be worried???... =/ Thanks for your time.