Could I be pregnant??????

I had sex two weeks ago and we used a condom most of the time but he took off the condom with out me knowing I didn't find out until after we finished and it was on the bed instead of on him.  I asked if he came inside me he said No. But I'm still worried.... According to eve my period is due today but it's not here yet. I sort of feel the symptoms of my period coming but it hasn't showed up.