Are you sure you ordered those from Cackle? Your chicks are Easter Eggers, and Cackle does not mislabel their Easter Eggers as Ameraucana. And they only vent sex their Black Ameraucana. Their Blue and Lavenders are not sexed. And none of your chicks are Lavender.
Cackle has Black, Blue, and Lavender Ameraucanas all available as sexed for 2017. Ask me how I know this... Not that I've been obsessively looking at their availability list on a daily basis or anything, ha!
https://www.cacklehatchery.com/pdf/AvailabilitySpreadsheet.pdf
Apparently the head spots blur after a few days so that method is more reliable in the first couple of days after hatch. And the barring on the feathers is supposed to be more prominent on the male chicks, but all the signs seem to mixed on my chicks so I thought I'd get an expert opinion. I guess I'll just have to wait another couple of weeks