Twinging kidney pains in my left side?

just over a year ago now i felt a really sharp pain in my left side just below the rib cage, it was the most unbearable pain iv ever felt but it went away after a few minutes, ever since then iv been experiencing twinging pains which usually occur when i move in a twisting position or when i, laugh, cough and usually after iv been drinking alchohol although i sometimes feel a dull ache and even shooting pains in that area, its not painfull just really uncomfortable iv been to the doctors 5-6 times now done numerous urine tests and had a blood test and nothing showed up, im gettin a scan soon, but untill then can anyone help me, i do drink at the weekends and feel its down to that and if so what could it be?