SweetLilBaby
All eggs have the little disk thingie. What you're looking for specifically for fertile eggs is the disk thingie will look like an O or a bullseye. It's a very distinct ring, not just a solid circle.
If you do a search, I know they have tutorials and photos somewhere on this BYC that have good examples of what you're looking for.















I love my little TJ hens and roos.
They're too cute!




. They're our first chicks/chickens! Gosh. I wish they could all be hens! 
