The hatchability of an egg plummets after being stored for 10 days. But that doesn't mean they cant be hatched.I usualy store mine for up to 2 weeks, but its better to settle for fresher ones. Eggs should be stored in a cool place...not unlike a fridge....but not as cold as a fridge....a base met or some dark closet is fine. I've seen hens get broody with a nest full of 15 eggs, they usually only hatch14 though, meaning that the first egg they layed, was stored up to fifteen days and didn't hatch, and the second egg she layed was stored up to fourteen days and hatched just fine....hope this helps