I get a lot of pain in my left kidney, sometimes the pain can be severe and make the kidney spasm been checked for kidney stones and infection?

Maybe not kidney. There are a bunch of organs in the area of the kidneys. If you have been checked for kidney problems, and cleared, check other organs, gi, gyn, pancreas, spleen, liver/gb, lymph nodes, musculoskeletal, even lung. See your doc.
Urologist. I would recommend you see a urologist for a more detailed examination. You may need some special x-rays and/or cystoscopy.