NL50 set against possible flush

[dersl]

Full Tilt Poker, $0.25/$0.50 PL Hold'em Cash Game, 6 Players
LeggoPoker Hand History Converter

SB: $51.70
BB: $50
UTG: $50
Hero (MP): $49.35
CO: $56.85 30/15/2.6/28(60)
BTN: $28.95

Pre-Flop: 7[img]/images/graemlins/spade.gif[/img] 7[img]/images/graemlins/club.gif[/img] dealt to Hero (MP)
UTG folds, <font color="red">Hero raises to $1.75</font>, CO calls $1.75, 2 folds, BB calls $1.25

Flop: ($5.50) 9[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/diamond.gif[/img] (3 Players)
BB checks, <font color="red">Hero bets $4.25</font>, CO calls $4.25, BB folds

Turn: ($14) Q[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">Hero bets $9</font>, <font color="red">CO raises to $18</font>, Hero calls $9

River: ($50) 2[img]/images/graemlins/diamond.gif[/img] (2 Players)
Hero checks, <font color="red">CO bets $26</font>

Easy call? Do you like my turn play? I was not sure whether a shove would be good because there is probably no worse hand that would call a shove...