Hello, and I hope I can help you today. First of all, the cramping and pain you are experiencing with urination are most likely symptoms of a urinary tract infection or UTI. UTIs have nothing to do with your method of birth control, and can potentially spread to your kidneys, so you should have an evaluation with your local physician to make sure you do not have a bladder infection. Regarding weight gain and its relationship to taking birth control, modern low-dose pills in general have been shown to not cause weight gain across the general population. If you have been on the pill for longer than three months, it wouldn t be unreasonable for you to see your women s healthcare provider and see if an alternate brand of pill might agree with you better, but there are usually other reasons in addition to the pill why someone would gain that much weight in a short period of time. So in summary, your burning and pain with urination has nothing to do with your birth control or your gaining weight. You should see your local physician or healthcare provider to have your urine checked to make sure you do not have an infection and if you do, to get appropriate treatment. I hope I was able to adequately answer your question today, and that my advice was helpful. Best wishes, Dr. Brown