Hi, Paula.
I'd say that one big mistake I made was trying briefly to lie on my left (surgical) side a few days after leaving the hospital. Did you, by any chance, place weight there just before the pain began? In my case, the pain began almost immediately after I lay on that side.
Those few minutes on my side caused a fair amount of pain, and it lasted for a couple of weeks (it contributed to the marked discomfort I felt going over bumps on the bus). That was a little disappointing, since till then I'd been feeling reasonably chipper.
I can't say I felt anything special precisely where the kidney had been (though I'm not sure), and I certainly didn't feel anything moving around in there. Still, I definitely recommend staying off that side for a nice long while.
Be well, Snoopy