Could I have an STD?!

Patient: A few weeks ago my boyfriend gave me oral sex. We are both virgins and neither of us have had partners before. He had no sores on his lips and was clean. Lately Ive had a slight itch down there but a few days ago I put tea tree gel down there (only after did I read that it was for external use only and a bit had got into my vagina) and it caused swelling, pain, a slight itch and bleeding. It doesnt itch all the time…more when I think about it. Could it be a healing process from the tea tree accident or could I have an STD? I have been putting cream down there which dries things out a bit…could that be a contibuting factor to the itch? Any answer would be so much appreciated.