10 weeks! That is amazing. Well, they are living animals and you never know.
Yeah, the comment on the pullet eggs is that the pullets eggs are usually fairly small and the eggs will get bigger as the hen gets older. With the smaller eggs, the baby inside often does not have enough room to position itself properly for the hatch, so it will often die in the shell. Some pullet eggs will hatch and do fine, but the hatch rate is usually not as good as you get with the bigger eggs. I've tried it and I had a lot better success with the eggs from the older hens.