When does the preload on steam start

I have a slow connection so I might need a little to download everything, does any one know if there is gone be a preload? Cause on Masseffect 2 there was none.

its already out in US and Canada.

if your in a part of the world where its not out there is no pre-load.

thats a shame but I may be able to dowload it from a friends internet and than make a backup game copy and import it to my PC.