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The Big Bang theory says that universe is flat. If the density of universe is less then the critical density and is proportional to square of Hubble constant the universe will Expand for ever. If the density of universe is greater then the critical density the gravity will pull the universe in another singularity
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I was always under the impression that it was gainsayed that the universe would expand forever, and that one of the amazing things about the expansion is that the density is just a bit less than the critical density to avoid a Big Crunch - the door is ajar!
Now that the universe is known to be accelerating in its expansion and taken as flat, this must be the final nail in the coffin for the Big Crunch.
The acceleration must in itself deny the BC as the gravitational pull of contraction is constantly getting less and less. As in, if it was going to a BC, it would be doing it now.
Relating back to the OP, if the pre-universe was identical and obeyed the same laws as ours, I fail to see how it could be contracting.
The place of dark energy is the mystery ingredient it seems... but even though we have not defined it per sa, the observations of its interaction (taking that the acceleration is caused by dark energy) with the universe seems to logically point only in one direction - expansion.