What Causes Abdominal Pain And Dark Spot On Gallbladder Ultrasound?

I went into the ER with severe (9-10) abdominal pain. When the Dr pushed on my abdomen it hurt on top right side and directly over my belly button. I had abdominal xrays that were unremarkable. The next day I had an ultrasound that showed gall bladder stones and shadowing over my left kidney. I periodically get pain in my lower left abdomen as well & it was very painful while doing the ultrasound over my left kidney by my back ribs. I have an appointment with a GI surgeon scheduled next Tuesday & am very scared. Last night and again today I had generalized abdominal pain. What could this be? A follow-up CT scan is recommended for my kidney shadowing/conturing.