If it makes you feel any better, my 2 Australorps are 22.5 weeks old and 21.5 weeks old and neither of them have started to lay yet, though the older one has been squatting for a week now. Both of them have combs and wattles that are quite a bit bigger and much more red than the ones in your picture, so perhaps they just have to mature a bit more?
I have a feeling that the really unseasonably warm weather up here (seriously, we're having weather that usually Florida or Texas gets -- 85%-95% humidity and in the upper 90's for temps . . . ) is forcing the australorps that I have to not lay, it really is hot and they're panting a lot, the poor things, and somebody here was just explaining that there's something about the CO2 exchange that gets wonky in this case . . . I forget the details, but it's pretty evident to me that the heat is probably responsible.
(this doesn't explain why our Black Sex link has laid 8 eggs in 10 days, including during this heat wave! Except for today, but then yesterday was a true corker . . . )
My younger Australorp isn't squatting, but our black sex link has been laying since July 30th and she *never* squatted, nor does she now, and she also doesn't do the egg song thing. She also lays at roughly noon (within 12-1pm) *every* time, obviously our little Black Sex Link hasn't read the Chicken Laying Manual yet! LOL!
Just wait, from the pic it looks like yours still have some growing to do
You can search my posts for a picture of what my Australorp's combs and wattles looked like . . .my first egg post should be around here somewhere.
HTH,
Whitewater