There are many possibilities, but my best guess is that you have touched or brushed against another cat or something the cat marked. Your cat smells this on your clothes and is now confused. She doesn't know why that cat smell is in the room that used to be hers. Try washing recently worn garments and wiping down sneakers. Try loving her outside of the bedroom to let her know you still love her. Offer her something from your room that you know she likes, but put it outside the room. Also, check to see if an outside cat is coming to your window and perhaps marking it with his/her scent. Be sure to close your window when you leave to prevent the smell from coming inside.