lump in right side

I have a kidney stone in my right kidney. I found a lump over there and when you press on it it really hurts. The doctor didn't notice it when I went to the dr. but when I went back for my ultrasound results I only saw the nurse and I mentioned the lump and he asked her about it and she said it could be the stone. She didn't come and check though, Could this be something else? Would the ultrasound have shown if it was? Should I go back? It feels like it got bigger and its starting to worry me.