I have a broody Silkie that has been sitting, there’s one egg left. Today is day 24 and no sign of hatching, no peeping or anything. I candled it a day ago to make sure it was viable and it looks like it should be ready. The air sac is large. Is this normal for an egg to go this long? This is my first time hatching. The other chicks that hatched are with another Silkie. Just wondering how long I should let it go before taking it away.