Hi there,Im a 28 year old female had almost exactly the same experience as you. Blood in urine and frothy urine with a cold when I was 26. Doctors couldn't explain it and I was sent for exactly the same tests as you were. All came back normal. As did my kidney filtration rate. I continued to have microscopic blood and protein in my urine on dipstick testing.I knew it didn't feel right although the doctors dismissed me, so I did some intensive research and discovered a rare condition called IGA Nephropathy. The symptoms fitted mine exactly, as did the onset. I took this information to the doctors and pushed for them to act on it. I was referred to a nephrologist who was amazing and agreed with me that this was IGA.I was so scared when I discovered all this, and I want to say to you please don't be scared! If this does fit your situation, you have caught it very early and will be able to take steps to manage it. In two years I have remained completely stable in terms of my kidney function, although I continue to have blood and protein in my urine. If you want to talk more about this, I am here and very happy to help as much as I can.Look after yourself.