did i play this AK hand correctly?

Please comment on this hand, especially the turn.

I have no read on UTG and MP2, MP1 is very tight (11/4/2 after 300 hands)

PokerStars 0.10/0.20 Hold'em (7 handed) converter

Preflop: Hero is Button with A[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/spade.gif[/img].
UTG calls, MP1 calls, MP2 calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, BB calls, UTG calls, MP1 calls, MP2 calls.

No raises, so not that tough a field. whatever that means at this limit.

Flop: (10.50 SB) 6[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(5 players)</font>
BB checks, <font color="#CC3333">UTG bets</font>, <font color="#CC3333">MP1 raises</font>, MP2 calls, <font color="#CC3333">Hero 3-bets</font>, BB folds, UTG calls, <font color="#CC3333">MP1 caps</font>, MP2 calls, Hero calls, UTG calls.

MP1 caps. he has something, i'm suspecting high PP, or maybe AKs-AQs. Pot is quite big, so i call.

Turn: (12.25 BB) A[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
UTG checks, MP1 checks, MP2 checks, <font color="#CC3333">Hero bets</font>, UTG calls, MP1 calls, MP2 calls.

MP1 slows down, so i bet. maybe he has QQ! utg and mp2 worry me, as i have no reads. but top 2 pair...gotta bet, right?

River: (16.25 BB) 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
UTG checks, MP1 checks, MP2 checks, <font color="#CC3333">Hero bets</font>, UTG folds, MP1 calls, MP2 calls.

again, passive field. bet again. but i'm not sure if i have beaten both of them. maybe both have beaten me. what to do in such cases?

Final Pot: 19.25 BB

any comment welcome.