Plan worked??

I got a period 5 days after taking the plan b. I’m sure it’s a period and not just withdrawal bleeding because it was extremely heavy, the usual 5-6 days, and had blood clots. I’m also for sure it was a period because I had missed my period in August.

Should I still be worried about pregnancy? We also used a condom when we had sex, if that helps.. I took a plan b cause not sure if the condom unrolled.