A couple of days ago, on Dec the 2nd, my boyfriend and I had unprotected sex. The next couple of days on the 3rd and 4th we continued to have unprotected sex. Every time we did have sex he came in me. Before that, we had also had sex on the 18th of November but I had taken the plan b. The 19th and 20 we also had unprotected sex and he came in me again. This whole week i my boobs hurt. Ever since I had taken the plan b I was getting cramps. My back hurt, headaches and now I have really bad Nausea. I don't know if it's in my head but on the 5th of December I got my period. It started off first as really light and pink but it got super heavy. Is there a chance I could be pregnant?