How many days after the ureter stent removal should blood remain in the urine? it has been 3 days since the stent removal and there is still noticeable blood in my urine?

It depends on many things. Reason for stent, how long in, and your ureter's reaction to it. I would suggest it will clear up in a few days if you drink plenty of fluids. If it does not let your Urologist know

It is not unusual the blood tinged urine persists more than 5 days but you should see it gets clearer everyday until you no longer see it with naked eyes.