i have pain that started saturday on my right side lower back. it does not feel muscular. it mostly hurts when moving the area, like sitting down fast or bumping into something, or walking to fast. it feels internal. sunday i developed what feels like menstrual cramps, but are not. Today the pain has shifted to my front side, same side, and sorta goes back and forth. The pain will alleviate when I urinate for a short time.