They will lay regardless of what you feed them. The biggest difference between layer feed and grower is that layer has more calcium. Layer feed does not trigger laying, it gives them the nutrients they need to produce quality eggs. I start to give my pullets layer feed when they are 20 weeks. Laying age varies by breed and their enviorment. My hens didn't start laying until 24 weeks. I would finish the bag of feed you have and start with the layer on the next bag. I have also mixed the last half of the grower with the layer. You could probably do that this week.
