Help!

OK so, me and my fiance have had unprotected sex for almost 2 years. (I know, shame on me) but He always pulls out. Last time we had sex his dick jerked and then he pulled out and came. He was worried that he might have Cum inside me. We are getting married in 2 months. But I don't want to be pregnant yet. Anyway. Here's the problem. For the past 3 days my vagina has been swollen and sore/burning and I have no idea why. When I put soap down there, it hurts really bad. Maybe its a yeast infection? How do I get rid of this? Please tell me in not pregnant.

Thanks