Should be soon.
If you pick one up and hold it like a football with her head facing back, feel above her vent for her pelvis points. If you can fit three fingers between the two points then laying is imminent. If they're closer together, then they're going to take more time.
Should be soon. Mine have all started around 21 weeks. We got four last spring, and four more this spring, all Feb hatch dates. They all started mid-July. Keep in mind amount of light exposure matters. Not sure where you are in the world, but daily light has been decreasing, and this could be impacting them.
How many hours of light (natural and artificial) do they get a day? Should be around 14 hours.
Are their combs and wattles pink or red? The redder they are, the more likely they are to begin laying.
My three EEs are from a mid February hatch. No one has lain an egg yet. My two Buttercups and two Welsummers are miss March hatch and none of them are laying either. All the rest are bantams at the same ages. Of 4 d'Uccles, 6OEGB, 5 bantam Cochin, one seabright and one black Rose comb bantam only two OEGB, two Cochins, and one d'Uccle are laying. I'm starting to get frustrated. The five standard hens I sold to a friend haven't lain yet either, same hatch dates-Anconas, red star and silver laced standard Cochins. It seems like everyone's big girls are laying but the ones I raised. I'm in eastern NC so we still have long days and warm nights. The buttercups and one of the EE have had red, larger combs for well over a month, but still nothing.