What Causes Pain In Abdomen Near Pelvic Area?

Hello,
I have been having a pain like pressure that is not severe on one side at a time then the pain starts on the other side. Left and right abdominal area near pelvic. The pain is gone during the period and it hits back once the period day ends. I am not sexually active and I am not pregnant.
I also have a pain on the sides where the kidneys are but my kidneys function Test is good. I am not sure if that pain is related to the first one. Note I got no discharges

Please advise