Double xp for no reason?

Games Other Halo
1

So, I pre-ordered Halo 4 like almost everyone else… yet i’ve noticed something. Say i get 2500 xp for one game, it adds to my progression as 5000, yet i’ve never been on any double xp websites (being from the UK i’m unable to use dew xp and the like).

Is anyone else experiencing this too?

2

Yea iv noticed this too and I’m from UK, have u got normal or limited edition? Iv got limited!

3

Perhaps you made a commendation go up, or you completed a challenge?