Rabbits do 2 types of droppings, a neat dry round ball, and a more wet loose stool, which they eat (to recyle the minerals out of them) as they pass them. Why you might be suddenly discovering them is because you bunny is pregnant, she is too fat to reach her bottom to eat her droppings. You will need to ensure her bottom is kept clean off the wet stools. I would only be concerned if the stools had blood, or was almost liquid like.