I am flying in 2 weeks with a 4mm kidney stone which is in the bottom of my kidney. minimal to no pain. will the flight altitude make the stone move?

No, but...: Changing altitude will not alter the odd for this 4-mm stone to move, but its timing of moving and dropping is entirely unpredictable so air pilots are advised to be stone-free. As to air passengers, it is up to their choice and risk. Besides, personal past history of stone disease may be a good reference to project how possible a stone in kidney may move, but still not 100% certain. Best wish ...