Are my duck eggs okay?

[FirstDuckEggs]

I found out that one of my ducks has laid some eggs outside of my property and has been sitting on them. I transfered them into my incubator where they've been for the past two days. I just candled them tonight and they all pretty much look like the pictures. I've never done duck eggs and was wondering if half of the egg being empty is normal, are they okay?

 

[Rooster G]

Normal, but rapidly changes. Find a hatching calendar for ducks.

 

[bon93]

It’s normal. You just got them at the early stage of them developing. They grow quickly and before they hatch they will take up all of that empty space besides where the air sac is. Just make sure to rotate them 3-4 times a day. Also keep a eye on the humidity and temperature for them is very important.