BUN/Creatine question

Okay I posted in the MSK forum but I thought I'd post here too. I was told I had MSK via two ultrasounds and I have had numerous blood/urine tests since. The tests have all been done within a two month time frame-


1st) Blood- BUN 10, Creatine 0.8, and BUN/Creatine ratio 13. In my urine- no protein or blood.

2nd) Urine- Occult blood 300, protein 30, leukocyte esterase 75, no infection

3rd) Blood- BUN 16, Creatine 0.7, and BUN/Creatine ratio 23. In my urine- no protein or blood, high white blood cells             but no infection.

4th) Blood- BUN 22, Creatine 0.7, and BUN/Creatine ratio 31.9. In my urine- Blood 2+, red blood cells 25-50, high white blood cells.

I just had another urine test done and they're trying to culture it. What does a increasing BUN mean? How can you tell the difference between Medullary sponge kidney disease and polycystic kidney disease? Can pregnancy cause damage to kidneys that have MSK?

I have tested negative for autoimmune diseases

Thank you so much any replies would help