Early period

I am not looking to get pregnant. But my boyfriend and I hadn't seen each other since August and when I went to see him at the end of October, we had a lot of sex obviously. I had just gotten my period from the 20th of October to the 27th and I went out to see him on the 29th and all of a sudden I got my period 5 days after I left him on the 8th of November to the 14th of November.  It was pretty heavy, lasted 7days, and seemed like a normal period. Do you think that I am pregnant? Is this implantation bleeding? I'm freaking out. We used protection the whole time.