Has anybody ever experienced this?! For those that don't know, it is the buildup of fluid in the kidney(s). I'm experiencing it on the right side, and holy crap is the pain awful. I literally am in more pain now than I was after my csection with my first pregnancy. My Dr ordered an ultrasound yesterday and didn't see any stones anywhere. But, last night I passed 2 small clots (basically the size of the plastic things on the end of a bobby pin) while urinating, and then from then on I bled each time I urinated. The pain while urinating is ridiculous. What I'm thinking is that I have a stone that is causing the fluid back up. But, maybe the stone was already heading out when they did the ultrasound so they didn't detect it. If anybody has ever experienced hydronephrosis or kidney stones during pregnancy, please let me know your experience!