[Lord of Angmar]

I believe that our universe would be the main universe and alternate universes would be created based on the choices we made in our own universe.

This is a rather contradictory statement which opens up a deeper philosophical idea. If we decide to go right in that fork in the road, how do we know that we are not the one's who are creating a new universe, while the old universe you decides to go left. It is a paradoxical question that cannot be answered. If the theory of mutliple universes is correct than there can be no "main" universe discernable.