Black Australorp - Roo or Pullet 5 weeks old

[Idaho Chicken Mama]

Hey Everyone! I've been researching sexing Black Australorps and I'm at all loss here, so I'm hoping someone might have experience with this breed and help me out
We added to our flock this year and I was so excited to find Black Australorps at our local feed store. They were supposed to be pullets, but I have a feeling that the Australorp on the right is a roo and the Australorp on the left is a pullet. These babies are 5 weeks old (I realize this might be too early to tell..) and neither seem larger than the rest of the 5-week-old chicks we have.
Any thoughts?

 

[HorseGirlAbby]

The one on the right is definitely a cockerel, and the one on the left looks like it might be as well.

 

[Grind Hard Farm]

Cockerels x2

 

[Idaho Chicken Mama]

Shoot! Are Australorps difficult to sex at birth? Or did I just get incredibly unlucky...

 

[LavenderDaFlerf]

Both cockerels.

 

[LavenderDaFlerf]

Shoot! Are Australorps difficult to sex at birth? Or did I just get incredibly unlucky...

Probably just unlucky, I bought three Speckled Sussex sexed "pullets" last week and I can already tell one is a cockerel.