Getting pregnant on birthcontrol

Patient: Would it be possible to get pregnant on birthcontrol and still get periods? Ilast had sex on Sept 10 and got my period Sept 13 I bleed for 5-6 days . It isDecember and I have NOT missed a period. Yet I have gained a heightened senseof smell, really sore breasts, and an ache in my pelvis for a few weeks now thatwil not let up. I have gained weight. but never had nausea or morn sickness.Took HPT that is neg. Just worried about these symtptom…Thank you