Broody made a mess of the nest on day 18

[Grandchicks22]

Bacteria can get into the egg and grow, and kill the chick.
This can happen with any eggs, but poop on the eggs makes it more likely, and a clean nest makes it less likely.

Since they were doing well on day 18, I think yours have a pretty good chance of hatching, but of course nothing is ever certain when dealing with chickens.

Okay thank you for your help!

Let the waiting game begin!