Just getting around to answer your question. I had two eggs that weren't doing anything after all the others hatched. I candled them and they looked dead, so I made a small hole in the top of the eggs and looked in. They were dead. One was the duck that I had put into the small mini bator....seemed to be way too much humidity. The other was in the regular bator and seems to have died about 5 days before hatch.., Still had huge yolk attached. So, that was the end of that hatch. Of the 10 eggs, I got 7 chicks and 1 duck. (80% hatch rate) Not as good as the 94% I had with the last hatch using my bigger incubator. The small mini was not good....only 50% out of 6 eggs, I don't think I will be using that small bator again.
You may want to go ahead and candle those eggs to see if there is any movement.