I have a hen that hurt her leg a few weeks ago, I had to separate her from the rest for a week as they were being mean to her, anyway she didn't lay any eggs while separated. She is starting to be in the nesting boxes, don’t know if she is back to lying yet; I wonder if it came from her? If she stopped lying when injured, could that have left an undeveloped egg inside her that went bad & now she finally passed it?