Questionable call?

1st hand at the table, hence I'm posting a newbie blind.

PokerStars No-Limit Hold'em, $0.25 BB (9 handed) pokerhand.org hand converter

Button ($4.40)
SB ($24.75)
BB ($24.15)
UTG ($15.30)
UTG+1 ($20.15)
Hero ($15)
MP2 ($39.05)
MP3 ($18.80)
CO ($9.65)

Preflop: Hero is MP1 with As, 9s. Hero posts a blind of $0.25.
UTG calls $0.25, [color:#666666]1 fold[/color], Hero (poster) checks, MP2 calls $0.25, MP3 calls $0.25, CO calls $0.25, Button calls $0.25, SB completes, BB checks.

Flop: ($2) 6s, Ks, Ac [color:#0000FF](8 players)[/color]
SB checks, BB checks, [color:#CC3333]UTG bets $15.05 (All-In)[/color], Hero calls $14.75 (All-In), MP2 folds, MP3 folds, CO folds, Button calls $4.15 (All-In), SB folds, BB folds.

Turn: ($35.95) 9d [color:#0000FF](3 players, 3 all-in)[/color]

River: ($35.95) 8h [color:#0000FF](3 players, 3 all-in)[/color]

Final Pot: $35.95

Results in white below: [color:#FFFFFF]
UTG has Kc 6c (two pair, kings and sixes).
Hero has As 9s (two pair, aces and nines).
Button has Qs Ts (high card, ace).
Outcome: Hero wins $35.65. UTG wins $0.30. [/color]

Given the results it looks fine, but watch out in future for when you feel the pusher has a set, this can cause a lot of damage to your odds.

Top pair aces with a nut flush draw? I can't get my money in there fast enough! good call