I dunno, I think it would depend on the size of the tank. My 20 gallon long is cycling well with Rosy Reds. I started with 7 Rosy Reds and one Crawdad and needless to say, two weeks later, I'm down to 2 Rosy Reds and one Crawdad. That d*mn Crawdad sure loves to eat the Rosy Reds at night... Anyway, two weeks into cycling a brand new tank I'm already seeing measurable amounts of Ammonia, Nitrite and Nitrates. I'm sure the Crawdad has a lot to do with it, but either way I'm hoping to have my tank fully cycled within the next two weeks.
And in the OPs case, if he does indeed have eggs the extra Bio load brought about by the fry should help. I'd say feed them a bunch and you should be fine, it just might take a while.