Please Evaluate

[kosmicd21]

ok, this is from the 40k guaranteed on party. We're into the third hour now and the blinds are 300/600 and average stack is 7500. I pick up 99 in middle position. Let me first say that 4-5 hands before this I had 99 in the small blind with 6.9k in chips and called a shortstack push and got rivered. Ok, back to the hand in question, I have about 5200 chips and i get 99. Person UTG doubles the blind to 1200. The earlier 99 may have affected me a tiny bit, because when it is folded to me I go all in (note: based on past play, i know that UTG does not double it with monsters, he either has a low-mid pp or two overs, but not AK). Unfortunately for me, the BB wakes up with AA and sends me packing.

Now imagine you didn't know the results, would you have pushed with the 99 or just called? and if you just call, i assume BB was gonna reraise, so do you call/push on his reraise or lay down the nines? Also, if you say call the original raise to 1200, where do u draw the cutoff chipstack at which point you push all in rather than call?