What Causes Pain In Vagina?

hi im 15 years old, i am 5ft 2 and i keep having pains on the left hand side under my stomach towards my vagina and sharp pains on the left hand side on the lip of my vagina towards the back. my periods started to be regular but then i had the pill and then depo injection and then i had the pill again which i kept stopping to take and then start taking again. but now i have stopped taking any contraception and have not had a period since last october. i have had blood tests and urine tests that have came back clear. i would like to know what is causing these pains as im scaired that i will not be able to have children when im older.