There's a ton of possible answers. You may not even be hearing the same bird you saw earlier, u have to assume it could be another bird. He may have got poached, coyote dinner, or another tom or even a bunch of jakes maybe ran him off. I doubt all those hens are incubating yet, but youre south enough, i guess its possible. All i can tell ya for sure, is this is exactly the reason why you have to scout continuously and especially dont rely on info more than a few days or weeks old, as things constantly change and affect patterns. Atleast u know this now, and not later. Just keep scouting and adjust your plans accordingly. You'll be that much closer to filling your tag. Good luck!