kidney pain and blood in urine

[trackandbandmom]

I'm a 35 yr old woman. About 80 lbs over weight.  5'3" 210 lbs.  1 1/2 yr ago i had my first kidney stone involving extreme pain which I passed.  3 weeks ago I woke up with blood in my urine and what felt like another kidney stone about to pass.  Nothing happened.  Haven't passed a stone.  Went to my family doctor.  Had a CT scan with no dye.  No stone detected.  Went to urologist 2 weeks ago.  Still blood in urine but no longer visible.  Been straining urine since and still no stone or stone fragments.  I still have constant pain in my right side that is bareable for the most part.  Sometimes it's like a "stich" in my side.  Sometimes it's more in front and sometimes it's more in my back.  But always on the right and never stops.  Been feeling very very tired lately.  Urinating more often than usual.  Going back to urologist in 4 days to see if blood still in urine.  If so then will have a catheter with a camera on in to look at bladder...Anyone have any idea what may be happening?  I'm really scared...