What is this?

[goldie1234]

Several of my eggs had this sort of spot this morning. I threw one out about twice this size.

 

[junebuggena]

Just a meat spot, nothing to be concerned about. The egg is still fine to eat.

 

[aart]

Meat spot or blood spot.

Caused by tiny blood vessel breaking when ova is released,
or tiny piece of tissue breaking off somewhere along the way.

Nothing to worry about, it's pretty common.

This video is quite informative and shows how it happens.
Egg Formation Video