I have a 19 week old Buff Orpington whose vent looks different today. I noticed her walking around and her vent was protruding and retracting, almost like she was trying to poop. After a few minutes this stopped and she went on about pecking, with her normal puffy butt self. She didn't seem to be in distress, eating and drinking fine. Could this be a sign of impending egg laying or something to watch and be concerned about. My first chickens, by the way.