Question about when exactly to put fertile eggs under a broody hen

[chickenmom22]

My hen went broody 2 days ago and she is still on the nest, but I won't be able to get a hold of the fertile eggs I want until tomorrow. Will it be too late by then? This is my first time doing this.

 

[Tiana's chickens]

No not too late, is she's serious broody she will patiently wait.
Also it's best to slip the fertile eggs under her at night and take the non fertile ones away. Then candle the eggs a week later at night and take away any that aren't developing.
Happy hatching

 

[chickenmom22]

Thank you so much for the help!