I just had my first hatch. So far out of 12 shipped eggs, 6 have hatched. One came early. Two were on time and 3 were a day late. The last 3 to hatch have protruding navels and one is worse than the others. What did I do wrong? And how do I prevent this in the future???? The bator ran about 99.6 with humidity around 40-50% with about 65% humidity at lockdown in a forced air bator.