Is it just me or is the USPS the slowest mail in the world?

I placed a few orders 3 weeks back, since then I have also placed orders in China and the UK.

A week and a half later I received my orders from Chine and the UK but I still don’t have my US Orders.

Is this normal for orders from the US to Australia and how long are you orders taking to get to you? I’m actually getting worried!