Fluid in kidney

Leticia
Hi girls I'm 20w2 days. Last week was having pains in my abdomen, went to the dr baby and I were fine. Past two days I have had pain in my right side lower back. Today I went to the Drs and they did an ultrasound of my kidney and found some fluid. Baby is okay thank God. I am going to a urologist tomm now. Has anyone gone through this? I'm afraid.