X2Yes. Also they can appear in non-fertilized eggs. I particularly get them from one chicken and I don't have a rooster. It's normal. If your friends ask why they don't see them in their store bought eggs you can explain that during quality control they screen out the eggs with blood spots and use them for other purposes, like when you buy a loaf of bread or another processed item that contains eggs as an ingredient. This way grocery store customers never see the blood spots but the eggs can still be used.