How old is he?I have a cockeral here that just started crowing 2 weeks ago and he is definatly fertile as I have hatched some of his chicks out.Without checking I would say he is 19 weeks old now.
You say you wouldnt want to eat them incase they are fertile?Is that because you would rather hatch them out?If its only because they could be fertile it makes no difference to the egg untill they start to incubate them.
If you do decide to hatch some make sure you mark the hatching eggs so that if another hen lays in the same nest you know what eggs are fresh and what is being incubated