Polycystic Kidney Disease (PKD) Support Group
Polycystic kidney disease (PKD) is a progressive, genetic disorder of the kidneys. It occurs in humans and other organisms. PKD is characterised by the presence of multiple cysts (polycystic) in both kidneys. The disease can also damage the liver, pancreas and rarely the heart and brain.

Menstrual blood is leaving the uterus and exits the body through the vagina.
Blood in the urine leaves the body through the urethra, having come from the kidneys, down the ureter via the bladder.
There is no reason why having an IUD means you can't use tampons. The tampon goes no further than the vagina and the IUD is safely tucked away in the uterus. If you use a tampon and still have blood in your urine, you will know that it's not menstrual blood. Menstrual blood can vary in colour at different times and blood in the urine can also vary from deep red to pinkish. I don't recall an odour from the blood in the urine.