First, don't count your chicks until they hatch. Second, learn how to properly store and incubate hatching eggs. I know that t we humans think that it looks easy peezy because.......
One: We have seen too many Disney flicks, and
Two: even a dumb hen can do it so hatching eggs is a snap for us smart humans.
That is without factoring in the millions of years of experience chickens have accumulated hatching their own young.
People, its called instinct.
I am not trying to be super critical but rather remind all of you to learn everything that the chickens have learned over the countless centuries that they've been making chicken babies.
If it works for our fowl and it'll work for you.
One more thing, you are reading these words on the WWW. There is zero, zip, nada guarantee that what you read or buy on the internet is even half way accurate.