Freaking out need help😞

I had sex on November 28th and I got my period Dec 2-6. I know it was a a real period because I had back pain, medium bleeding, and even blood clots in my pad. The bleeding was also continuous. I've been super nauseous and I've had continuous breast pain and soreness for two weeks. Is it possible I'm actually pregnant or could it be implantation bleeding that I had. I'd love someone's idea of what it is I'm freaking out and having panic attacks over this :(