AK River decision

[MagicFlea]

after 32 hands, villain has yet to bet/raise after the flop (24/3/0)

Party Poker 2/4 Hold'em (7 handed) converter

Preflop: Hero is MP1 with A[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">3 folds</font>, SB calls, BB calls.

Flop: (6 SB) 4[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, BB checks, <font color="#CC3333">Hero bets</font>, SB folds, BB calls.

Turn: (4 BB) A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets</font>, BB calls.

River: (6 BB) 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets</font>, Hero calls

not exactly a scare card, but it seems if he has a raising hand I beat (pretty much any A) why did he wait for the river? The fact that he hadn't bet once after 32 hands swayed my decision. I still think I'm ahead, but I'm risking 2BB in a 8BB (after a call) pot if I raise to see I'm beaten. What say you?