Panicking!!

Hey guys! So I had sex on Christmas eve and we used the withdraw method. I started getting nervous about him maybe not pulling out in time so I got the plan b approximately 31 hours after sex. My period is due in 4 days but I'm freaking out because I keep reading that plan b doesn't work if you've already ovulated and we had sex the day of my last fertile window. I don't have any symptoms yet but is there a possibility I could be pregnant?! 😩😭😞