Been taking cipro (ciprofloxacin) for 7 days now for a kidney infection. 500mg 2x per day. I am still having kidney pain. How long should the pain last?

By now-should b gone. After 7 days of the meds and dealing with the infection, the pain associated with it should be resolved. Follow-up with your dr. As maybe the infection is resistant to Cipro (ciprofloxacin) or other things are going on as well. Best wishes.
Should be better. Contact your doctor and discuss with them an see what they want to do.