It looks like it could be a "Lash Egg" (Salpingitis) which is inflammation of the oviduct. Did you keep it? Did you cut it open by chance - any multi-layers inside it? If caught very early some people do have success with treating infection with antibiotics. Do you have a vet that can prescribe meds for you? http://www.the-chicken-chick.com/2014/12/salpingitis-lash-eggs-in-backyard.html http://www.the-chicken-chick.com/2015/03/causes-of-lash-eggs-salpingitis-by.html
No, i didn't keep it/poke at it. I had to lock the chickens up and go somewhere and forgot to save it. Thank you for the info, it's sounds about right.