We are in a similar situation. It just dawned on me that one of our 5 month old americaunas (or EE?) is a boy. He/She has a dark pink comb, is larger, and has always been more aggressive, and stands off to the side when I bring treats out (letting the ladies eat first?). A few days ago, he bit down on a barred rock's neck and mounted her. Finally, today, he looked directly at me and cock-a-doodle-dood! What are your expert opinions? And should I worry about fertilized eggs? We have 10 chickens altogether and 4 are laying. The picture below was from 2 months ago.
Yep, this is a rooster. You'll have fertilized eggs, but so do many folks here. Embryos don't start developing until the egg had been incubated at 100 degrees for a few days. Just collect your eggs every day or so and you'll have no problems. I've had roosters with my laying flock for 20 years and never had a nasty surprise when I cracked an egg.