Hi, I've been searching all over for something like this as many years ago I DID find a foreign object in an egg and it's been bugging me ever since. No one is going to believe this BUT....
The object was a halfpenny piece, I absolutely kid you not. I broke the raw egg into the bowl, the yolk and white were both perfect. It was only when I looked at the shell that I noticed the halfpenny lodged in the end with the air sac (it didn't fall into the bowl with the rest of the egg). I am 100% sure I wasn't imagining it, neither was the coin in the bowl beforehand as it was stuck in one end of the shell. There must be a way this is possible, I don't know how, but this is proof enough for me!
Maybe some kind of deformity within the internal organs? It is possible as I saw it with my own eyes!!