Thx everyone for the explanation. I kinda had a feeling that was the case. We'll be 18 weeks at the end of the month so I'm starting to keep an eye out for eggs. I still have the nest boxes blocked off. I've definitely noticed some changes in the older birds; their combs are starting to grow taller and wattles are starting to come in. I also notice some color change. I find it interesting that one my EE's comb area is super red now, but she's one of the younger ones (13 weeks.)
The ducklings are about 2 weeks old today. They're jerks, but at least they're cute

.
That reddening of the combs can drive ya nuts when you're waiting for pullet eggs!
If you watch closely, the combs can redden up and then pale out again with exertion or excitement.
The best way I've found is to feel the pelvic points, here's my notes/blurb about onset of lay:
New layers can be quite goofy acting, they don't know what they are doing at first and can be confused and anxious, it can take up to a month or so before they get it all figured out. Putting some fake eggs or golf balls in the nest might help show them where to lay. They may scratch around in the nests for weeks before laying. Meanwhile, eggs everywhere, some of them can be rather funky looking, soft or thin shelled, huge double yolked eggs.
Squatting:
If you touch their back they will hunker down on the ground, then shake their tail feathers when they get back up.
This shows they are sexually mature and egg laying is close at hand.
Combs and Wattles:
Plump, shiny red - usually means laying.
Shriveled, dryish looking and pale - usually means not laying.
2 bony points on either side of vent:
Less than 2 fingertip widths apart usually means not laying.
More than 2 fingertip widths apart usually means laying.