When one of our bantam hens first started laying, she laid an egg the size of a peanut m&m. It was a proper egg though, had a yolk and everything. We blew it so that it wouldn't go bad.
This is not the first egg. She has been laying for about 6 months, although she just finished molting. She layed normal ones yesterday and the day before.
One of my girls gave me a tiny one like that. They consistently layed medium to large eggs before and after and I even get a jumbo/double yolk about once a week. It was almost a normal egg the yolk was just a streak of yellow. I cooked it up sunny side up and the dog loved it.