Is it normal to have shifting in my teeth after only having veneers for a few months?

That does seem odd that your teeth would shift that noticeably. What I don't truly understand is why one of your veneers would cause a shift of a tooth like that. I would need more information such as photos in order to understand why. Obviously, if a veneer would cause a shift like that, you wouldn't be responsible and that should be a relatively easy fix without a full Invisalign type of situation. 

Teeth seek a position based upon a balance of forces.  The tongue muscles push forward and the lips pull back.  Where these forces are equal is termed the "equilibrium zone".  It is possible that your veneers are in conflict with the equilibrium zone.  Another possibility is that when you slide your teeth forward the veneers do not contact equally.  In any case teeth only move when forces are applied.