I am having pain in lower abdomen (in centre) while urinating during periods since 4 months. I have got Urine culture test done and no bacteria / fungus growth was there in culture. I got abdomen ultrasound done too and no abnormalities were found. I have this pain only during 2nd day of periods and no pain on any other days. Also i did not have this pain before 4 months. (I have repeated urine culture 3 tumes and ultrasound 2 times but the reports had no issue at all) Is this kind of pain normal ? Else, what could be the root cause ?