PLEASE send some advice my way!

Aliya
Hello! Here's my situation:
I'm currently on nuvaring, which functions by having it 3 weeks in, 1 week out. Sunday was my day to take it out (to allow for my period) so I did. 
My boyfriend and I had sex that night, and his condom broke. He came, and I know for sure some was inside me. The next day, (Monday) I was in a major panic, so I went and bought Plan B. 
It's Wednesday. I woke with some serious cramps, and thought I would be bleeding. But I'm not!!!! Wtf is going on?!?!? Am I pregnant?!??