Pregnant?

I had unprotected sex with my boyfriend about 24 hours ago. He came inside me. I woke up this morning having period like cramps, and have had it all day.. but I am not supposed to have my period til the 13th. I am currently ovulating. Can this mean im pregnant? It feels just like period cramps. We did that the day where it was 33% possible. Whatcha think?? :)