I picked up 2 Isa Brown pullets at the first week of May that were supposedly “point of lay” age. So roughly 20 ish weeks or so. Now over a month later they still have not started laying and their combs aren’t nearly dark enough to indicate that it’s coming any time soon and they are not squatting. Is it possible that they are younger than advertised? Pictures below. For size-reference, they are with a mix of adults, 11 week old chicks, and a Jersey Giant roo so it’s hard to judge. 
