@pipdzipdnreadytogo
Okay....saying it again....
When I candled the eggs from my broody I saw nothing. By somewhere around 16-18 days I could tell that they were
dark and solid. That's it.
All of the dark solid ones hatched.
By that same time I could tell if the interior was "sloshing". (No chick

)
So....my point is that if I had tossed them before that I would likely have tossed live chicks. I just was NEVER able to see anything inside prior to that. By that time they were heavy and solidly dark and produced chicks.