Also, the egg may be infertile. Have you candled the eggs? I put two layers of egg crate in my egg boxes because the eggs can "bend" into the holes of the crate and touch the wet substrate. My guess is that egg either got too wet on the bottom and is going bad or it was never a good egg to begin with. I would candle then let them be. If the egg gets moldy, hard (solidified solids within the egg) or smelly you will know for sure.