Sometimes chickens are put back a bit by the stress of a move. Also some people will sell you pols at 16 weeks knowing full well that they havn't laid yet. watch for the colour of the comb and wattles, a healthy chicken in lay will have good red wattles, if they are pale it is either not ready yet or a bit out of sorts. have you given them any tonic and grit?Are you giving them layers pellets or mash? Sooner or later they start laying and you will wonder what to do with all those eggs.