Could I still be pregnant?

Had raw sex with a guy a week ago today. He came in me, and after he did, I went to the bathroom and started bleeding realizing it was day one of my period. Took plan B that night then the bleeding immediately stopped. So now it’s a week later and i’ve had spotting all day to now full on bleeding. Does this mean i’m not pregnant from the sex last week?? Or is this just the original period i was supposed to have ? Basically my question is, Do i still need to be worried about pregnancy?