period???

so I shouldve started my period 2 days ago. I do have sore breasts, but that’s about it. I had sex like 2 weeks ago without a condom, but he stopped early so he definitely didn’t cum in me, it’s just the precum I guess that im worried about..i took a plan b in late January, could it be messing with my periods still to this day because it’s trying to adjust? is it possible I could be pregnant?