I have a young kitten, about 18 weeks. Today she shat on my bed. Two days ago she shat over the side of her litter tray. We got her about 4 weeks ago. She is eating and drinking fine. She usually uses her litter tray well, no problems with using the litter. I always clean out her tray as soon as she shits, and completely replace all of the litter once a week. We have no cats or other pets in the house. What could be going on, and I'm assuming this isn't normal?