Worst pain everrrrr,, I get them with every pregnancy this is my 4th, I passed the stone and caught it in a cup thing my doc gave me, he sent it to the lab to test it and see what was built up in the rock, and to my surprise it was all the minerals from the prenatal pills, I quit taking them and have been feeling great, I am now 24w, I try to take one pill every 1 to 2 weeks because I feel the need to, but yes I've had them several times with my other pregnancys and never knew why, good luck.
I went and had an ultrasound done today on my kidneys and bladder. But I won't know anything till Monday since my doctor isn't open on the weekends.. I peed out some sand earlier. So hopefully it will pass soon. It is just VERY painful.
Go see somebody. Those things aren't friendly at all. Few weeks ago I had to take my sister to the ER at 5 am because she was passing one.