how will i know when an egg stops developing?

[aelizabeth]

the title says it all..

my hen quit sitting on an egg @ day 11. I put her back on the egg (she's staying on it, so why'd she get off in the first place?) but I think the egg might've stopped developing.

will I be able to tell?

 

[Mandalina]

yup,candle it in a few days and if it isnt alive you will see that.