25NL AQ flops top pair vs coldcaller

[Grandezza]

Villain is 50/0 over 10 hands.

Full Tilt Poker, $0.10/$0.25 NL Hold'em Cash Game, 4 Players
LeggoPoker.com - Hand History Converter

Hero (BTN): $43.80
SB: $27.60
BB: $62.85
UTG: $26.35

Pre-Flop: Q[img]/images/graemlins/diamond.gif[/img] A[img]/images/graemlins/club.gif[/img] dealt to Hero (BTN)
<font color="red">UTG raises to $0.85</font>, <font color="red">Hero raises to $2.90</font>, SB folds, BB calls $2.65, UTG folds

Flop: ($6.75) A[img]/images/graemlins/spade.gif[/img] 7[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/club.gif[/img] (2 Players)
BB checks, Hero checks

Turn: ($6.75) 9[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">BB bets $6.75</font>, Hero calls $6.75

River: ($20.25) 2[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">BB bets $20.25</font>

What do you think about checking behind the flop?
Given how I played the hand I gotta call the river right? I just tend to find that these mash pot bets usually means they have it.