I would not count on this.I've read about a float test. Has anyone tried it with any success? I also wonder if the same tests with duck eggs, as that will likely be my next batch of hatching eggs.
You're supposed to be able to see if the egg is moving while floating,
but a live chick may not be moving at the time you float.
Just wait another day or two, broody will get off the nest to show her chicks were to feed and water after a couple days.
You say it's day 22, what day did the other chicks hatch?