One of the cats threw up a puddle of blood. Because we weren't sure which cat it was, we ended taking the two possible suspects to the vet. {We were only there a couple of days ago for injections and check ups] Turns out Willow has a high temperature due to a throat infection so it was most likely her that threw up the blood. Poor cat is definitely not herself. I don't think I've ever seen her so docile. lol. She was given an injection to reduce her temp and anti biotic paste for the infection so hopefully she'll be on the mend soon. . 
