I've had my puppy for a month now and she's always been very good about waking me up when she has to potty. Her accidents in the house have been very minimal as she only likes to go on the grass. The past three nights she's pooped in the bed and she's never done that before. I've put her in the kennel for the rest of the night but I would feel bad crating her every night. Every time I find the poop in the bed and say her name she automatically cowers. She lowers her head and puts her tail between her legs and goes and tries to hide behind a pillow. So she obviously knows what she's doing is wrong. Any suggestions?