I incubated an egg from my chickens in a small plastic incubator, meant for one or two eggs. I purchased the incubator from a hatchery. The directions for incubation were followed up until the end. The chick did not hatch on day 21 of incubation. There was movement (I think a heart beat) felt in the egg on day 23 of incubation. The chick did not hatch by day 25 of incubation. I opened the egg on day 25. Inside was a chick still sealed in the membrane fully formed except the tail end of the chick seemed somewhat mushy and oozed a yellow creamy textured liquid from a hole when very light pressure was applied. what was this liquid. Was the chick actually not truly fully formed? why would this happen? does this just happen sometimes? I would like to incubate and hatch a chick but I don't want to try this again and bring things to life just to make them die.