How To Treat White Cluster Like Blisters Inside Right Buttocks Region?

I have small white cluster looking like blisters on inside of right butt cheek. last sexual partner was in february. was at the obgyn yesterday and he looked at it and said if they become bigger or painful to come back. he asked if i have ever had herpes but i have not. he also said maybe cysts. said he could see hair folicle and everything. What could this be? Its irritating and going on the 3rd day of having them