Is your rooster actually doing his job?
If you are planning to incubate, you need to know if your eggs are actually fertile before dedicating 21 days to them. The easiest way to check? The breakfast test! 
When you crack a fresh egg open, look closely at the yolk.
Fertilized (Blastoderm): You will see an organized, clear ring that looks like a tiny bullseye. This means the rooster’s contribution has successfully met the hen’s cell.
Unfertilized (Blastodisc): You will only see a small, irregular, solid white speck. That is just the hen’s cell.
Pro tip: If your eyes are playing tricks on you, take a photo of the yolk with your phone and apply a Grayscale or Graphite filter. Stripping away the yellow color instantly boosts the contrast and makes that bullseye pop!
However, keep in mind,
A Blastoderm does NOT guarantee a chick.
Just because it is fertile doesn’t mean it will develop 100%. Rough transit, shipping damage, or incorrect incubator conditions can easily halt development. Also, this bullseye structure physically breaks down under the heat and moisture of an incubator. If you crack open a failed “dud” egg on Day 21 expecting to check for a bullseye to see if it was fertile, you won’t find it. The structure usually degrades beyond recognition within the first week of incubation.
