If you free range, they may be laying out in the range area...if they are showing other signs of laying maturity, lock them up for a week or so and see what you get.
Signs of onset of lay---I've found the pelvic points to be the most accurate.
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.
Tho I have found that the combs and wattles can look full and red one minute then pale back out the next due to exertion or excitement, can drive ya nuts when waiting for a pullet to lay!
2 bony points(pelvic bones) on either side of vent:
Less than 2 fingertip widths apart usually means not laying.
More than 2 fingertip widths apart usually means laying.
Free range birds sometimes need to be 'trained'(or re-trained) to lay in the coop nests, especially new layers. Leaving them locked in the coop for 3-4 days can help 'home' them to lay in the coop nests. Fake eggs/golf balls in the nests can help 'show' them were to lay. They can be confined to coop 24/7 for a few days to a week, or confine them at least until mid to late afternoon. You help them create a new habit and they will usually stick with it. ..at least for a good while, then repeat as necessary.
Your protein levels might be low, read the nutrition info on your feed bags and adjust what you give to eat so that they are getting 16% protein at the very least.
I like to feed a flock raiser/grower/finisher 20% protein crumble to all ages and genders, as non-layers(chicks, males and molting birds) do not need the extra calcium that is in layer feed and chicks and molters can use the extra protein. Makes life much simpler to store and distribute one type of chow that everyone can eat. I do grind up the crumbles (in the blender) for the chicks for the first week or so.
The higher protein crumble also offsets the 8% protein scratch grains and other kitchen/garden scraps I like to offer. I adjust the amounts of other feeds to get the protein levels desired with varying situations.
Calcium should be available at all times for the layers, I use oyster shell mixed with rinsed, dried, crushed chicken egg shells in a separate container.
Animal protein (mealworms, a little cheese - beware the salt content, meat scraps) is provided during molting and if I see any feather eating.