First timer, help with deciding if egg is viable

[DSJMHenDen]

I decided to hatch some backyard mix eggs for a family member. Today was day 9. 2 of the 12 were clearly not fertilized. 2 are very dark and I honestly don't know how to tell if they are viable or not. 1 is a white egg, and I'm pretty sure it's no good now, but I don't want to make a mistake. I used a second flashlight on the darker ones because i could not see anything. First timer here, so any help appreciated!

 

[Debbie292d]

You should be seeing what looks like a spider inside: a blob with veins coming off from it.

The first one, I can't tell. The second one I see no blob or veins but are you sure that's at Day 9? Usually they aren't that full looking at that point.
The one on the right for sure doesn't look fertile.

 

[DSJMHenDen]

You should be seeing what looks like a spider inside: a blob with veins coming off from it.

The first one, I can't tell. The second one I see no blob or veins but are you sure that's at Day 9? Usually they aren't that full looking at that point.
The one on the right for sure doesn't look fertile.

In theory, they all should be day 9. They aren't from my girls since I can't have roosters. I can kind of tell just by the colors and shapes that there are probably 2 from 6 or so different hens. The 2 that were not fertilized were both very similar looking eggs. 7 that were either brown or white clearly had veins and a little blob moving around. The dark ones (olive eggs) I couldn't even see anything with the built in candler. The last photo (40) is a large white egg, so I was more skeptical of it since I didn't see veins. I've read so many posts I'm just scared about exploding eggs .

 

[Ridgerunner]

I've read so many posts I'm just scared about exploding eggs .

It is pretty horrible when it happens but it doesn't happen nearly as often as you would think from the posts on this forum. They are caused by bacteria getting inside the egg and multiplying.

The eggshells are porous. If bacteria start growing inside you can smell that rotten egg smell. If you notice the rotten egg smell sniff each egg individually. You will be able to tell which one is bad.