This morning i found a fully formed egg inside a whitish colored sack that looked like a deflated ballon. The egg appears to be fully formed with a shell but encased in this film? I also found it in the roosting box beneath a perched bird. Has anyone seen this before? Is it a health problem? The hens are about 2yrs old. I purchased them (4) from a small organic farm near me. They've been laying consistently since having them but i've never seen this before. Thanks!!