I had/have eggs set to hatch tue I went to turn the eggs fri night and 1 hatched out,so I took the rest out homemade turner so tonight I had 1 more.whatcould have caused them to hatch this early? and why so far apart?
So day 21 would be on the 2nd of March? Friday would've been day 17... I think I heard that smaller eggs will hatch slightly faster, but at the same time, hear it's the same as standard/big eggs. I'm not sure about why it hatched on day 17, but it's only a day before lockdown/expected start of hatching so I wouldn't worry too much unless it looks underdeveloped.
Although it is true that a higher temp will cause eggs to hatch earlier, this is still just a generalization, or an average. In other words, if you have 20 eggs in the incubator and 15 hatch early, you could probably assume that more than likely your temps are a little high.
However, with two eggs not hatching the same day, I would assume that they just developed a little differently.
Just like people babies, some are born earlier than others and really, it doesn't mean anything except that some develop more quickly than others.
They hatch when the baby is ready. People babies and chickies.
I sometimes have one hatch early because they weren't in the right position to pip internally. So they start needing oxygen to breathe and come busting out of the egg early. However hatching on day 18 seems extremely early.