Kidney Problems or just all in my head?

I have never had a kidney infection before but my lower back (just above my "love handles" hurts on both sides, sometimes more on one side than another. I also have had pain on lower left and mid right side of my stomach and pelvic area (which I think may be large intestine problems), I do not have a fever (but I have been prescribed a high dosage of ibuprofen which is a fever reducer). I have had some bladder issues also (sudden urges) but it is more like my bladder doesn't tell me when I have to go until my bladder is full and ready to burst and then I go a large amount with no pain (Had many UTI's in the past and no symptom of one and urine test confirmed) I been feeling nausea and unbalanced. Could this be a kidney infection without having a UTI, and if so would testing for a UTI show a kidney infection or is there a separate test? (and no, I am not pregnant or PMSing)