What Causes Itching And Swelling In Vagina?

hi i am having itching, very slight burning, and im swollen inside and a little out on my vagina. i have had a pap test and nothing came back bad for it when i had it. it hurts when i have sex cause its soo swollen i have had it alot lately but stoped for awhile cause i got my period. i thought me not shaving there was creating problems. its not burning alot just a bit itchy and like i said swollen.i am on ortho evra. is it a yeast infection? i know im not pregnant cause i had my period and i had a test done a week before my period as well that was negative..can someone help me?