Could I Be Pregnant?

I had sex with my SO last week. It was in the shower and unprotected which gave me a little bit of anxiety, but he assured me that he didn't come inside of me at all. Now I've been ridiculously fatigues and I'm having cramps. I'm not supposed to start for another week/week and a half. I know the symptoms of pregnancy take longer than a week, but we've had sporadic unprotected sex for a while now. Could I be pregnant?