I began setting my eggs on November 19. They were all from the same kind of chickens and started at the same time and they started hatching as they should have on December 9th. By Sunday the 10th all were hatched except for 3. I have been wetting the eggs every evening since then. Normally after the 2 day of them still not hatching I would have discarded those last 3 but I have seen one of them moving when I put them in a bowl of warm water. What could be the cause of this one egg taking an extra 6-7 days to hatch???