Could I be pregnant and still getting my period?

Patient: I am a 33yr old woman. I have had endometriosis for 10 yrs. I have been trying to conceive for 6 months. I have gained 15lbs and 2 bra sizes in the last 2 and a half months. I had my period on oct. 7 ,2011, nov, 2,2011, and nov. 25, 2011. It is dec. 8,2011 and I have started to spot, which is unusual for me. I feel like I’m pregnant. Is it possible?