My last attempt at hatching eggs I started with 11 eggs. two were not fertile, two got blood rings around day 7ish and bought the farm. and one died for unknown reason around day 12. I had six that looked great. On day 20 I had two hatch, and a third on day 21. the other three looked great on day 18 when I last candled all of them and took them out of the egg turner and placed them on their side on the mesh floor of the incubator. I waited out the other three until day 25. None of the three ever started to pip. I opened the eggs to see what happened and all three were fully developed, by their level of development they must have died around day 20 or 21. One was head down in the egg, but the other two looked fine. What possibly could have happened? I'm worried for this next batch as I have 8 looking great with 4 days to go.