Waiting for egg to hatch! Need help!

[amy4189]

Hi have one duck egg in my brinsea min incubator. I started with four but he's the only one that made it this far. The duck was always moving around any time before I candled it but I did not see any movement in the egg at day 26, the air sac was large, I could see feathers along the dark part of the air sac. I candled it quick day 27 and still no movement. Is it possible that it's just not ready to hatch, or did I lose it? What are signs in the egg that I can tell if the duckling is dead? Really upset it may not hatch. I should mention that the temp was well regulated and I was spraying the egg once a day