This has happened to me a few times - I’ve cracked an egg into a bowl, and noticed what appeared to be spots of blood, and sometimes tiny lumps of tissue. Why does this occur? Does it mean that the egg could have been fertilized before being collected? And, are such eggs safe to eat? I’ve always thrown these out, just to be safe.
Well guess what, you are pretty close!
It is a fertilized egg!
The egg is fertilized BEFORE the shell is formed around it.
Then it is laid and later collected. Toss away. 
Eating such eggs is a matter of preference AFAIK. I believe the Chinese and some other oriental culture consider old/aged eggs a delicacy. As the farmer said as he kissed the cow “Everyone to his own taste!” 
"Mommy, my egg tastes bad. "
“Stop complaining and just eat it.”
“Mommy…”
“What now?”
“Do I have to eat the beak?”
I fish it out, because it looks nasty. But I still eat the egg. Just not with a friggin’ scab fried into it.
Not necessarily. I’ve seen plenty of blood spots in eggs that I know weren’t fertilized (my family raised chickens for years, and didn’t keep roosters in with the hens we used for eggs).
I’d just pick out the spots (cooking tongs work well as tweezers, albeit large ones) and then use the eggs.
Unless they’re free range, the rooster would have needed a pair of bolt cutters to break into the hen’s cage.
Blood spots do not mean the egg is fertile.
They are fine to eat.
6 responses and not a single link to the relevant Mailbag article??
I used to have a silly aversion to eating eggs with blood spots in them, owing largely to a misinformed Home Ec teacher who told us they were bad and must be thrown away. They seem to be a lot more common here in South Africa, though, so I’ve had to retrain myself to just use the egg as normal, or I’d be throwing away a dozen eggs a month.
So far, I’m fine. The leprechauns in the bread bin agree.
I never eat eggs with blood spots, even though I know they can’t hurt me. They’re just a little too gross.
I once had a dozen double-yolk eggs. Now I’ve heard they separate the doubles out and you can buy them that way, but my carton wasn’t marked as such. It was very weird.