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Tho the pink thing at 10:00 looks kinda of like one, I don't think it's a developing embryo, there would be veins all over if it was.
The whitish 'U' shaped thing at 1:00 is very odd too.
Is the white thing above 12:00 a chunk of butter or was that inside the egg shell too?
There can be some odd pieces of tissue that slough off the reproductive tract and get encased along with or instead of a yolk.
They can be 'normal' glitches that you'll never see again or signs of disease if they continue.
I'd be opening your eggs in a separate dish rather than right into pan or recipe for awhile.
If you get another set it aside and do some dissection on those 'things', taking pics as you go along.
Keep the shell(s) too as it might hep you identify which bird is laying them and might have a problem.