Okay...how can I tell whether or not our BO is laying – and where?

The last couple of days, I've heard someone singing either the egg song or the 'Aaah! I'm freaked out!' tune (which I heard one of the girls doing after our neighbor's dog played tag with her ??? It sounded quite a bit like the egg song.). I'm pretty sure I saw one of the BO's doing it yesterday, but how do I know if she has eggs somewhere? They free range, and I don't know where she would have laid them. I found an egg in our shed when our first Gold Link started laying a few days ago.