1700 calories symptoms and conditions

Well...I guess I'm not crazy. My doctor assured me this pill was great...I'm finding that not to be the case! I was put on Femcon FE following the birth of my second child via c-section. Since starting the pill I have experienced headaches, depression and MAJOR WEIGHT GAIN. Prior to the pill I was about 3lbs. away from my pre-pregnancy weight. After 6 weeks on the pill I have gained over 12lbs. It makes no sense. I am monitoring my caloric intake which is around 1500-1700 calories per day. I attend a tough "boot camp" style workout 4 days a weeks. How can I be gaining weight? I'm considering just going off birth control all together. I'm 39 and our family is complete. I just can't tolerate this much longer.