I have 6 isa browns that are all over 24 weeks i get 4 eggs a day but my other 2 are not. Then my black sexlinks are over 20 weeks and nothing. Im still having trouble with them laying in the coop i get 3 in there but only 1 else where. Not sure how to tell if my chickens are laying or are not. Im new to having chickens.
Those are all high production birds...most should lay 5-6 a week..but maybe not.
If you are having trouble with them laying outside of coop nests I would confine them for a time.
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 (or longer) 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.
You can tell who is laying and who is not by checking pelvic point spacing.
Grab them off the roost at night, easier to 'catch' them then, and check them out.
Vent:
Dry, tight, and smaller - usually not laying.
Moist, wide, and larger - usually laying
Pelvic Points 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.