When buying storebought eggs, you rarely see the little red (blood) spots in eggs. Often they will fade over time and disappear but when eating eggs that are very fresh, you’ll often find those little spots. Some think it’s an embryo. It is not! Even eggs from my hens who are never with a rooster have those spots every now and then. If you care about the difference in fertile and non-fertile eggs, this is a good blog post done by pattypenny.blogspot.com. This is another very good article.
Unless the eggs have been incubated for a while and a baby chick has started to develop, what you see in those photos is the ONLY difference in fertile or non-fertile eggs.
Once the hen begins to incubate, all bets are off . . no way would I crack one of those eggs. I don’t want to see what’s in there!
Our eggs are gathered three or four times per day and even if it is a fertile egg, it’s taken from the nest and refrigerated before any embryo development occurs, unless the mama chicken is wanting to hatch babies. Then, if for some reason she loses interest in the nest or all the eggs don’t hatch, they’re tossed.
Fresh farm eggs are so totally different from storebought eggs in so many ways but no . . there are no embryos formed in any of the eggs we’re eating or giving to friends.