It's really best to wait to give layer feed to pullets until they are closer to laying, which is generally (depending on breed) 18 to 26 weeks of age.
Too much calcium can damage growing chickens. It builds up in their livers (or other organs) because they're not producing eggs yet, and is not good for them at all. You won't see any adverse effects until later.
The best thing to do is give them a flock raiser, "grower" or all purpose type chicken feed, until you change them to layer feed when, #1 they reach 18 weeks of age or so, OR #2 - they start to lay eggs.
If you wish, you can continue to feed "starter/grower" until then (although it's more expensive than general purpose feed).
Because I have layers AND young chickens, I stopped feeding layer feed and changed to all purpose feed, then put oyster shell out for the laying hens to eat "free choice." I just put oyster shell flakes in an empty tun can, nailed to the inside coop wall, near the feeder.