It has been hot here so I am luck any eggs made it. the momma hen has been loyal to her eggs due on mon/tues. one from a store and 2 from a local hen.
Up date, the local hen's eggs are 1-2 days more advanced than the store egg (local hen eggs pipping and peeping, store egg not in air cell yet). I will pull the babies as hatched and make the mom finish hatching the store egg then give them back at night when all are hatched.
Sometimes chicks of a certain strain just hatch early but sometimes it is from a little early incubation as multiple hens sit on previously laid eggs as they prepare to lay their own. In a cage free egg house as soon as each egg is laid in the box they roll to the back onto a conveyor belt and are sent to cold storage pretty quickly with no chance for extra incubation.