Pain when I urinate? Positive that it's not an STD.?

Birth control can throw off your periods; it will take your body a while to adjust to the hormones. As for the pain, it could simply be a UTI. I had one recently. Symptoms are pain when urinating, pain in the lower region of the back, bloody urine, etc. Symptoms vary from person to person. One might have pain, the other might only have bloody urine, or just back pains. You should google for a full list of symptoms. The bump could be a cyst. They are quite common and a visit to your OB can either confirm or deny that. Good luck!