I'm passing a kidney stone right now. After 15 or so, you get used to them. (My largest was 9.7mm, unpassable though. $27,000 in doctor bills [no insurance]). Pains can be in the back, in the front, both, or other places. The pain will come and go as the stone blocks urine flow out of the kidney. If the stone is irregularly shaped, and allows drip past it, you may not feel ANY pain. And despite what people may think, actually passing it out is painless. Good luck if it is!