Itching

Hi guys,me and my Bf have had sex and now I’m just itching and idk what the cause of it is..I think it might be a yeast infection because we both are std free how would I know if it’s a yeast infection without going to the doctor!! Do u guys think I could possibly be pregnant even tho I’m on birth control.. cause every home test I took turned out to be positive and I’m really scared please help 😭😩