Infection?

I am 16 and had sex while using a condom. A couple days later I started having itching in my vagina. I normally only feel the itching at night. I started spotting but if I'm starting my period then it's a little early. My periods are irregular. The last thing I want to do is go to the doctor so please don't comment you need to go to the doctor. I know I messed up but if there's anyone to help me that would be great. If it might be an infection, then I am
able to buy monistat. I have to pee more often. I don't know if it's from the condom, tight clothing, or what. If you know anything about this or can help me then PLEASE COMMENT