My period is late...

I know I'm probably being super paranoid, but my period hasn't come yet and I'm a little worried. My bf and I had sex when he came back from a trip and I rode him and when we finished, I climbed off and realized that the condom was stuck inside of me so just as a precaution he got me plan b almost immediately. I'm just nervous. Is it normal for it to make it a few days late?