Have kidney infection from strep bacteria normal ultra sound have tryed two diff antibiotics still in pain low fever what should be next step?

Pyelonephritis. Difficult to offer suggestions when full medical history is not available. If you actually are being treated for pyelonephritis you are hopefully being seen both by a urologist and an infectious diseases expert. You may need further imaging studies since the value of us is limited in this area. Sounds as if a change in therapy may also be warranted. Do not know what strep you have.