Chronic pain, accending colon or kidney problem?

Patient: I have a chronic pain on the right side, directly across and down a bit from the belly button. After passing a stool the pain (dull) goes away for a while. Then it comes back like a kidney infection, indeed it may be the kidney, as I can feel a slight discomfort down to the right testicle. I am on my 4th day of Tetracycline ( a year and a half old prescription my wife did not use) and am experiencing some bloating.