You said you haven't had sex. Have you had anyone perform oral sex lately? Im asking because herpes can be transferred through oral sex (if the person gets cold sores) as well as intercourse.
"More importantly, when oral herpes lesions and/or its contents come into direct contact with the genital area through oral-genital sex, genital herpes most likely will develop."
http://www.goaskalice.columbia.edu/0938.html
I found one website that states different reasons you can have sores that are not STD related. (yeast, contact dermatitis, infected hair follicle)
http://carefirst.staywellsolutionsonline.com/RelatedItems/78,vaginalsoresandlumps?Page=outsidethevagina
I hope what you have isn't an std but if it turns out to be something like herpes, theres always medicine that can help it from reoccuring.
Good luck
yes, some people with chlamidia dont have sypmtoms even 15 years after they have been infected
its very possible