OH, gosh, honey - I don't think that's an egg. It appears to be tissue...could be part of one of your girls' repro systems that came out! They can expel an ovary - it's unusual, but does happen. I wonder if that's what this is?
ETA: do all your girls seem okay? Anyone looking puffed up or not feeling well?
Go to this web site and click on the internal and false egg layer link and the weird eggs link. Does it look like the "alien egg?" http://www.browneggblueegg.com/Article.html