how long can an egg stay under hen and still be okay to eat?

[dftkarin]

I have a broody hen sitting on 6 marked maybe-fertilized eggs (from a friend with a rooster) but my othre hens sit on top of her and lay their unfertilized eggs (or she sometimes steals them from the other nestbox and rools them into her nest of eggs) and I feel terrible bothering her and rooting around in her eggs to look for unmarked ones - but I know there must be some in there. If an unfertilized egg stays under her (in the warmth) for two days or more - will it start to go bad and shouldn't then be refrigerated and eaten?

 

[soctippy]

I will refer you to a previous thread on this topic: https://www.backyardchickens.com/forum/viewtopic.php?id=175295