I honestly think every cat is different. Ruby filled her litter box in the hours immediately following birth. I think she was a bit "bound up" because her belly was so huge. She was producing BM's almost the size of a humans (sorry, maybe TMI). I would wait it out. If she didn't eat in the hours before labor, she likely doesn't have anything to pass. Ruby ate right up to and during her labor. I was hand feeding and watering her from small bowls from my daughter's tea set throughout her labor.