How long over the normal incubating period can an egg go? And why? I broke open my turkey eggs today, day 33 from when I set them under the hen. All were duds except one, and it had a live turkey poult in it. It had a yolk sac that was about 1 1/2" long, so it had a few days to go. A friend of mine had her chicken eggs (under a broody hen) hatch on day 26 and 27. I have no experience with turkey eggs, but I've never had my chicken eggs hatch out so late. Anybody have any ideas as to why?