Today is day 18, moved an egg to the lock down incubator. I candled it yesterday and it had a small air sac. When I candled it before placing in the LD incubator tonight, the whole inside is blacked out. I can not see any air cell now. Did it possibly pip inside early? I keep a record of each egg and it was right on track yesterday. No chirping or wiggling yet. Kinda worried now. This is my first D'uccle. I have more still in the rotating tray incubator, but again ... first one from my own flock. Have not had any experience with a smaller breed before. So was unsure.