Is there a way to preload the game if I preordered it on amazon ? Because i'd like to play the game when it is released, dont have much time for games.

Nope. Only digital purchases get the preload.

I guess that's what I get for buying the game at a higher price

Makes sense when you don't think about it.

As soon as you get your hardcopy (hopefully before the 10th) you can preload.

Hopefully

Depending on the retailer, it is possible that they could email the Steam code provided they have your email. Of course, this would not work if every physical copy is completely sealed up with no way for the retailer to get the code.