I'm still waiting for my incubator to arrive in the post (it should be here any day now) I figured that I would just put a few eggs in it (it only takes 7 eggs anyway) and candle them after a week. This should give me a definite answer for if the eggs are fertile or not.
I've already trimmed the chickens bums (LOL!) so this is really the final call to decide if I should get a new rooster or not.
I'll keep you posted and let you know what my findings are.
Thanks again everyone :-)