I have my first set of eggs that my hen is sitting on, I think we are around day 19. She has been collecting eggs every day since she first started to sit and go broody. I candled a few today, some are def not fertile, but some of the others I saw had the air sac in the bottom of the egg, and then were almsot all black/dark in the rest of the egg. I am using a crappy flashlight, so its hard to tell . Does this mean its hatching soon, or its dead?