Hi,
Welcome to the forum. I am really glad to help you out. In view of the symptoms, the possiblities which need to be entertained are urinary tract infection which can be confirmed by doing a urine analysis and urine culture. Endometriosis, fibroid uterus and pelvic inflammatory disease are other possiblities which should be ruled out.
Doing an ultrasound of the lower abdomen and a gynecological examiantion should help in confirming the cause of such a pain. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.