Right kidney lighter color

Hi there,I've just came back from the hospital where I've had a ultrasound done,the nurse said that my right kidney has a lighter colour than the left one,which looks healthy,bladder looks healthy too but I'm very confused to what it might be.The reason was,I've start feeling some pain in my abdomen,lower left side,and feel bloated,like the kidney is swollen.I always wake up with that disconfort and I have to urinate straight away as it feels I'm going to explode!There's no pain when I urinate,so I thought it was a bladder problem.
the nurse will refer me back to my doctor,and I'll have to go there in 3 days time,untill then,I am freaking out!anyone has seen this before?
thank you