I Recently Lay Had A Tendon Repair In My Rt

I recently lay had a tendon repair in my rt shoulder. The surgeon prescribed Percocet 325 mg . Pain was intense following surgery. My arm
M is in a sling. Am very uncomtable. Since taking melds every 4-6 hrs I find my left side loweback is hurting me. (Kidney) I am drinking 3-4 bottles water daily. My urniation is at least 6-7!possibly 10 x a day/night. Is there something wrong w my kidney? I am on thyroid melds/do loft/aspirin.