weird play on the turn

[kgrad5]

i dont know why i did it, it felt very wrong afterwards.. what do you all think of this? i have no reads.. new to the table, he has been playing like a regular 25 nl player..

Party Poker No-Limit Hold'em, .50$ BB (6 max, 5 handed) converter

BB ($8.75)
Hero ($23.5)
MP ($80.1)
Button ($15.3)
SB ($7.25)

Preflop: Hero is UTG with K[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/spade.gif[/img]. SB posts a blind of $0.25.
<font color="#CC3333">Hero raises to $3</font>, MP calls $3, Button calls $3, <font color="#666666">2 folds</font>.

Flop: ($9.75) Q[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets $9</font>, MP calls $9, Button folds.

Turn: ($27.75) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP bets $6</font>,<font color="#CC3333">Hero raises all in</font> MP calls $5.50.

River: ($39.25) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>

Final Pot: $39.25