That happened on my last hatch too. When I was candling the eggs to check for cracks and such before setting I did not catch it, but after a couple of days I saw it floating in there like a blob of super dark ink and was like huh??Hmmm, maybe. I set the egg anyway so...we shall see.![]()
The eggs were from my own flock and I have a couple who have spots occasionally, so I just kept an eye on it and it eventually hatched out just fine.