I just got my first egg yesterday, from a BA hen that I obtained as a chick in early March. I thought my BO that was the same age would be first but I was wrong. There were signs that the BA would lay. Her wattle was redder and more developed. Both of them had sung the "egg song". But the BA was also squatting on occasion. Yesterday, she had been doing the "egg song" and later went into the coop by herself and stayed for some time. It is unprecedented that she would separate herself from the flock for more than a few moments, but there she was. The other chickens came by from time to time to see what was going on. I waited outside for 30 minutes until she came out. I went in not sure what to find and there was a beautiful, well-formed, somewhat smallish egg. And afterwards I heard the REAL egg song, more like an egg opera compared to what I had heard before.
The great thing is that even though they free-range with all kinds of secluded places where she could lay, she chose to go into the coop and lay the egg in the nesting box. I was pleasantly surprised by that. I guess the fake eggs and golf balls paid off.