Pregnant?

So I take my pill religiously everyday at the same time. June 20th I had unprotected sex and he wasn't sure if he came inside of me. I didn't get plan b as I'm already on BC. My period is due this Wednesday but I'm starting to freak out and think my mind is playing tricks on me. My boobs are super tender, I have a headache and today I'm nauseous. All of which I normally get before my period except the nauseous feeling. Can anyone give me any advice to make me feel better? Definitely not trying to be pregnant right now .. I mean that's what they make birth control for!! I have never missed any pills but there is always a chance.