It doesnt say so, though: Unless this is clarified you should assume you get the attack.
Note that a Bull Rush standard action (the other alternative) may sound like an attack, but is more like movement.
You should also be aware of that even when making a bull rush as part of a charge, this doesn't allow you to exceed your normal move allowance. A normal human doing a charge from 50 feet away still can't bull rush his opponent more than 10 feet, even if the human's Strength check exceeds his opponent's by 10 or more.
Cinematically, this sounds like your round freezes in the middle of the bull rush (and that you're still in the bull rush by the opponent's turn), but by the rules there are no such special conditions. You are better off starting closer to your opponent if your DM isn't ready to make up house rules for such an unusual circumstance.