I have Chronic Kidney Stone Disease and everything you are describing is everything I have dealt with.
I even woke up one morning peeing blood. I thought I was bleeding out. It scared the crap out of me. I got on the internet and the first thing it said was the same thing you saw. Consider it to be CA. I about died. I couldn't believe it, I just knew I had Ca. The ER did a CT on me and found massive amounts of stone throughout my whole urinary system, at this point they all seemed to be moving, just causing alot of pain.
2 weeks later I was in the OR for a Lithotripsy. That was my first time to have one removed. Let me tell you something. My doc looked at me weird when I was telling him where the pains were. They were low, very low. I felt like something was poking at me on my pubic bone, it burned to an extent and I was cramping all the time. He swore it wasn't a stone that was stuck but the 2nd CT said otherwise, so he had to eat crow and do the lithotripsy.
Stones are weird. You hurt, then you don't, then you hurt like hell, then you don't, then you cramp, then it hurts in the flank, then it hurts lower, sheesh it will drive you insane. Sometimes its agonizing sometimes it isn't. The only symptom I have that is consistant is my right flank hurts EVERY single morning I wake up. Sometimes it takes the wind out of me to get up and sometimes it doesn't but it never fails, if I have slept on the right side, I am going to know it because of the pain. He still can't figure that one out.
I think he finally got aggrivated with me, I had been in 6 months in a row, crying to him, because I needed something for pain, they would go in and do a KUB and/or an IVP and he would see several in both kidneys and one or 2 down in the ureters. He finally had me do a series of 2 Urinalysis and sent those off to Litholink out of Chicago. Now finally after years and years and years of suffering with this, they determined I have hypocalciuria and hypooxaluria and elevated sodium in my urine. SO...diet change AGAIN and he is putting me on hydroclorathiazide and potassium cytrate. I go in for more lab work after being on the meds for 2 weeks and then 2 months after starting the meds I have another round of a 2 day urnine collection.
So I guess what I am saying is blood in the urine can mean anything and NEVER go to the internet to determine your DX. It will scare the crud out of you. Hang in there.
Oh one more thing, I think the reason it took so long (almost 20 years of blood in my urine and on some case urine in my blood
)to finally get on a path to recovery is because these Dr's kept throwing me in the "too hard to fix" pile and I kept having to find another doctor to help me.