I have a buff Orpington who is about 26-27 weeks old, and has been laying since 23 weeks.
A few weeks ago at around 1pm I went out to clean the coop and didn't realize she was inside in a nesting box. I was making a lot of noise, so i figured I startled her. she growled at me, and wouldn't leave the nesting box all day. Once the sun went down I went to check on her, and she still hadn't moved. I picked her up and put her on the roosting bars. She had not laid an egg. The next day I noticed she was growling at noises (I hadn't heard her growl before this incident). She also did not lay an egg that day. Finally after 2 days without an egg she laid a slightly deformed egg (It was fine inside).
I was out of town last week, and my wife Jessica was taking care of the chickens. 3 days ago she noticed the same pullet camping out in the nesting box. The next morning when Jessica checked on them, the Orpington had not moved from the coop. Jessica picked her up to make sure she was warm. She was warm, but had not laid and remained in the nesting box until I checked on her this morning. When I opened the coop she growled, and fluffed up (also have not seen her do that for extended periods of time) I picked her up, tried to calm her and get her to eat. She was very hungry. and pooped (all at once) about as much as a 50lb dog would poop. I had to go to work after that, and came back around lunch time to check on her, and she had plopped herself back in the nesting box showing the same behavior as before.
Her vent is clean, her comb is nice and red. Not sure if this is something to be concerned about or not, these are our first chickens. Any help would be very appreciated.
--- Figured it might be worth mentioning that while I was out of town she laid an egg that was normal size, but pretty abnormally shaped.