The only thing that i know of which would have those symptoms would be genital herpes.
The best thing is to have the bumps swabbed and then cultured and see what turns up. If there is a sexual health clinic in your town or city they would be familiar with the procedure. Genital herpes doesn't have to occur in or on the vaginal area. Herpes can occur anywhere within what is referred to as the "boxer shorts" area for men and women alike. Some people do get them on or in the genital area, but it's quite common also to get them outbreak on the skin of the anal area, butt cheeks, top most area of the thighs.
If you get the area swabbed and cultured it will either come up negative for herpes or if it's positive, they can tell you whether it's type 1 or type 2 herpes. Don't wait till the area totally dries up. It needs to still be moist for a culture to be done. At least if you do this you can find out what it is.
I highly doubt they are pimples as pimples don't hurt then itch in that sequence. If you haven't ever been sexually active then obviously there isn't a chance of it being herpes.
