BC and Pregnancy

I've been on birth control for over a year now and I stopped taking it in September and had my last period the 14th of September. I have not had a period since then and me and my boyfriend have unprotected sex and he does not pull out. Could I be pregnant? I took 2 first response tests 2 weeks ago and they were BFN. I'm nautious a lot and I eat a lot more than normal. My stomach makes weird noises and my back always hurts.