@so1frustrated Welcome to Mayo Clinic Connect. Having blood in your urine is not normal, and having what appears to be pure blood is cause for alarm. It sounds like you have had this problem before, but nothing was found upon testing. Correct?
Personally, I would run, not walk, to the nearest emergency room, or your doctor. Something is not right, and insisting on treatment may save you. I have chronic kidney disease, and have gone through kidney infections. They are no fun! If there is an infection, they may need to culture and see what antibiotics the infection will respond to. Without the correct medication, the infection will come back.
Please consider heading to the doctor right away, and let me know what happens, will you?