Flank
pain (
where the kidney is), if that is what you are describing, above the hip bone on the side, would make me think you might want to check on the right kidney, maybe get a urine test. Or, if below the kidney, again, it might be gas pain, which can come and go as the pockets of gas move along.
Pain in the upper right abdomen- could be gallbladder or bile duct, liver, gas in the transverse colon (common place for it to collect), costochondritis (if in the rib cage area up there).