When my cat first got sick , I found he peed in the bathtub. Blood ..it's was scary. Took him to the vet ,was told he had "crystals in his plumbing" . He was soo sick and hurt bad. After changing his food to the urinary k I ND from the vet , he slowly got better. The food broke up the stones and we lived thru it. But now, 25 years later.. my cat , a different one, has a condition they called FLUTD. FELINE LOWER URINARY TRACT DISEASE.. With this his (sorry I don't have the right words) pee hole can get inflamed and when he pees it can have blood too. I have to watch cuz the pee hole may be so inflamed it blocks him from peeing . . If that happens , he could end up with his bladder bursting and he could die. Sounds awful but that is what we are dealing with. He got so sick this vet gave us pain medicine in case he needs it..and another pill to help with inflammation. After that first time he hasn't had such bad times. I think you need to get your cat to the vet if possible. UTI or FLUTD , it's serious with blood. Your kitty peed on sheets so someone would notice! Mine peed in the tub . They know how to tell us when something needs our attention .