Help FFXIII: Missions question

[RollaRocka]

So I just finished chapter 11, going back to Cocoon.
However I rly want the chocobo egg (hope I name dit right, the thing that gives u 2x experience).
Is it possible in chapter 12 to go to Gran Pulse to train or do I have to finish the game ?
I can still load back, thats y Im asking...

 

[Raiiyokuu]

The Grow Egg.

If you really want to know --

SPOILER - Hover down with mouse.

Spoiler

Once you go to Chapter 12, there's no going back. Once you finish Chapter 13, basically the game, you can go back to Gran Pulse and anywhere else and do anything you've missed