AKo early against one opponent

[brer]

PokerStars No-Limit Hold'em Tourney, Big Blind is t20 (9 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

CO (t1500)
Button (t1490)
SB (t1460)
BB (t1500)
UTG (t1500)
UTG+1 (t1460)
MP1 (t1500)
Hero (t1500)
MP3 (t1590)

Preflop: Hero is MP2 with A/images/graemlins/club.gif, K/images/graemlins/heart.gif.
UTG calls t20, UTG+1 calls t20, MP1 calls t20, <font color="#CC3333">Hero raises to t60</font>, <font color="#CC3333">MP3 raises to t100</font>, CO folds, Button folds, SB folds, BB folds, UTG folds, UTG+1 folds, MP1 folds, Hero calls t40.

Flop: (t290) T/images/graemlins/heart.gif, 9/images/graemlins/club.gif, K/images/graemlins/spade.gif <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t300</font>, MP3 calls t300.

Turn: (t890) Q/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
Hero checks, MP3 checks.

River: (t890) 8/images/graemlins/diamond.gif <font color="#0000FF">(2 players)</font>
Hero checks, MP3 checks.

Final Pot: t890

I check in front both times because I figure to be behind. Am I wrong to think I am behind after the turn? What about on the river?