Too late?

I’m not suree if this is the right forum to post this...but I need advice.

This past weekend me & my bf went to Vegas & we had sex on Saturday, unprotected and he pulled out. It was my first time. We got home on Monday. & just to be sure I took a plan b pill. My period was supposed to start Sunday & I still haven’t started. According to the website for the pill I had 24 more hours to take the pill. Could the pill be affecting my period? Or could I have been to late to take the pill?