Kidney pain not stones or infection?

I'm just curious if anyone else has had this problem before and if so can tell me what that problem for them was. Last night I woke up multiple times to a pain in my lower back. When I officially woke up for the day, the pain was pretty bad to the point I couldn't comfortably lay on my sides. It started to subside on its own, although Tylenol/ibuprofen haven't helped much.

So, I started googling, and came to the conclusion something could be wrong with my kidneys. I immediately got really worried (as is common when you google your symptoms lol) that I could be getting a bad kidney infection, or worse, kidney stones. So, I went to a health center and got a urine test.

I have been noticing all day today and yesterday that my urine is a lot lighter than normal, however, when they asked for the urine test, I didn't need to pee that badly, so my urine came out very concentrated which led them to believe I was severely dehydrated. Since then, I have peed twice more back with the lighter color, so I don't believe I'm actually dehydrated. The tests for infection and stones were all negative.

Has anyone experienced something like this? It's pretty uncomfortable, and I'm glad it doesn't seem to be anything serious, but I hate being left in pain with unanswered questions.