Suggest Remedy For Pimple Like Bump On The Outside Of Vaginal Opening

I have a small pimple like bump that is red with almost a head on the outside of my vaginal opening. There is no pubic hair there, and I am wondering what this could be. I am paranoid it is herpes, even though I do not think it is. It is tender to the touch, but does not itch. It is solely one bump, and seems to be around my other (what i think are) sweat glands. I have had unprotected sex with a few men, but nothing in the past year.Help! This is the first time i've noticed something like this.