I have a blister in the inside of my vagina and i wanna know if its normal or what? i get them every once in awhile. i never had sex before but i do masturbate. its just one blister and not several. it hurts when i have to wipe after going to the bathroom. i really wanna know whats causing them to show up. i know it cant be STDs or anything cause i never had sex with anyone. Please tell me what they are and if there normal and how they appear or why?