Will my cock fertilise my chicks when they are fully grown?

[BuffOrpington567]

I recently hatched a couple of aymouth rocks which have both turned out as hens which is a good thing as I may want to breed them, but now at 7 weeks they are ranging with the my cock and his hens and I’m wondering since they have spent time together but not very close and obviously the cock doesn’t act like he does towards the hens with the chicks, will this make the cock not fertilise the chicks when they are pullets and able to hatch chicks if their own?

 

[aart]

A 'good' cockbird will not try to mate with a female until she is ovulating(laying eggs or close to it).