So sorry. I had a similar experience last month with my first time at incubating. I got the 'bator from a guy at work, and it's prob'ly twenty-plus years old. I didn't know the wafer should have been changed, and the temperature fluctuated drastic'ly. It went up to 107 at least once, and 106 another time.
Out of the nine eggs I put in, three were clear. I dropped one candling on day ten, a couple days after the first roasting. I felt terrible when I saw the little tiny chick with the huge eyes flapping it's little wings.
One hatched on day twenty, and I was ecstatic. On day twenty-one, there wasn't anything going on with the other four. Another hatched on day twenty-two, and I was over-joyed. There wasn't anything happening with the last three on day twenty-three, so I took the eggs out and buried them.
It's a big learning process. A good breeder is committed to doing the best job they can. You got a better thermometer, and I got a better thermostat. Next time, we'll both do better.
A good breeder must also be willing to cull an animal that doesn't meet certain minimum standards. Incubation length is one of those standards. There are people who say cull all unhatched eggs on day twenty-two, because if you don't, you can be perpetuating the genes that make an embryo develop slower.
And, feeling bad at accidentally killing an animal is perfectly normal. I killed and butchered twenty-five meat birds last year with only a little twinge. I have another thirty to do in four weeks. But dropping that one egg nearly had me in tears.
