Fertile egg?

[hatykuber]

I have a few duck eggs in my incubator that should hatch this weekend. I wanted to see if my chicken eggs were fertile so I could put some in the incubator after the duck eggs. I'm pretty sure they are fertile but always like hearing others opinions. Just cracked this one, is it fertile?

 

[SunHwaKwon]

It does not appear to have a bullseye.

 

[coloradowildflower]

I would guess no, but If I look close I can see why that one might be tricky. If you have another you can spare, check and see if there is a more distinct ring.