Duck eggs going bad? first time hatching and need advice.

[nelleyoukai]

So our pekin has been sitting full time for about 4/5 days on 15 eggs.
My partner decided to candle them today and mentioned that some of them are going dark?
I came in and had a look myself, and its really hard to explain what it looks like.. I'm assuming the air sac is the white circle at the bigger end of the egg? that looks fine. but where im assuming the yolk was its like someones cut out a square of dark paper and stuck it to the inside, it doesnt go all the way around so theres a gap on the opposite side which is completely clear.
I couldnt spot any veins in the dark but but it was hard to see properly because its the middle of the day and by the time i came back with a toilet roll and a better torch she'd jumped back on the nest.
Two eggs looked like this, and im just wondering if they've gone bad and if i should throw them away or leave them a bit longer or check them again when its dark and take a picture to show you what I mean.

 

[Amiga]

@dotknott

does this sound familiar?

 

[dotknott]

Hrm. 4/5 days I don't believe would be enough for a visual change if they were rotting.

If you can recandle after sundown in another 4 you might be better off. Seeing something this early can be difficult and veining might not be so pronounced as of yet.

 

[dotknott]

The darkness you describe: how big are you talking? 90% of the non-airsac space? The size of your pinky nail? The size of a single hole punch?

It goes around? Around what the inside wall of the egg on the meridian? Around the yolk?

Photo of this might be hard (candleing photos are really tough) but if you can even sketch out what you're seeing, that could help.

 

[nelleyoukai]

I've checked again (it's really hard to get out there when it's dark unfortunately) and for some reason there are eggs missing now, she's gone down from 15 to 12 and they're just gone, they aren't in the shed anywhere.
I was able to take some pictures today, and I checked all of the eggs, almost all of them look the same with the darkness taking over. There's maybe one or two that don't have it, I've taken pictures of two with the shadow and one without it.

This is one with the darkness, it's connected now too.
This is what it looks like from the front and the side.

This is the other one with the darkness, it's less developed than the first one, you can still see what I'm assuming is the air sac on top?
It shows the front, the top and two side pictures.

This is one of the eggs that isn't dark like the rest.
Taken from both sides and the top.

I have no idea what I'm seeing, and everywhere that I've seen online there's not a single photo like this.
I might just have to tough it out and crack one open but I'm a little scared to be honest haha.

 

[dotknott]

Well, I'm stumped!

 

[nelleyoukai]

It's really strange isn't it?? I mean do they look like this later on, is it possible that I've just miscalculated how long she's been sitting on them?

 

[nelleyoukai]

So I just checked again while it's dark out and the black part is all veiny and there's a little dark dot amongst the veins that kinda jiggles around a bit?

 

[dotknott]

Miscalculation of current incubation length could account for it, yeah. But wow that would be closer to 14 days not 4 days.

 

[nelleyoukai]

I really need to get a better torch with a more direct beam I think, or a better camera. I tried to take a photo in the dark but you can't see the veins, and the jiggly dot is only just visible. I've drawn an arrow to point it out though aha