I don’t think you should incubate these eggs, even if they are fertile, you will have better hatch rates if you get your own rooster. Eggs can last about a week, maybe more in room temperature, they can even hatch after being refrigerated sometimes. The real danger is getting warm enough to develop and then getting cold again, as that will then kill the new embryo.also how long can the egg last without heat before it dies as iv had these in a cold dark draw in outside shed for a few days now in near 1celsius??? Worth incubating these still or just try the next fresh eggs