Please help me

Hello, I am in major pain and cannot figure out what is causing it. I think it is my kidneys but I am unsure. 2 nights ago I woke up in major pain under my ribs, front to my upper back. I was also having a hard time taking deep breaths. Since then I have a dull constant pain in the same areas. I went to my gp and she found protein in my urine and has scheduled an ultrasound for May 1. I was wondering if anyone has any advice or guidance on what to do. I don't know if this is related but I had a baby 9 weeks ago. Thank you to anyone who helps.