The first hatch I set 22 eggs. 20 pipped,15 hatched. Eggtopsy revealed 5 fully developed chicks that didn't hatch. Next hatch set I set 18 eggs 9 pipped 6 hatched. Eggtopsy revealed 11 of the 12 that didnt hatch had developed chicks. Last hatch I set 24 eggs 14 pipped 13 hatched, 1 died with in a day of hatching. Eggtopsy revealed all but 3 of the unhatched eggs had developed. What am I doing wrong?