NL400 AJs basic question

[$upermad4it]

Party Poker - No Limit Hold'em Cash Game - $2/$4 Blinds - 5 Players - (LegoPoker Hand History Converter)

SB: $396.00
BB: $124.07
UTG: $662.00
CO: $398.00
Hero (BTN): $410.00

Preflop: Hero is dealt J[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/spade.gif[/img] (5 Players)
UTG folds, <font color="red">CO raises to $14.00</font>, Hero calls $14.00, 2 folds

Flop: ($34) 4[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/club.gif[/img] 8[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">CO bets $26.00</font>, Hero calls $26.00

Turn: ($86) Q[img]/images/graemlins/heart.gif[/img] (2 Players)
CO checks, Hero checks

River: ($86) 5[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">CO bets $45.00</font>, Hero calls $45.00

Pot Size: $176.00 ($2 Rake)

villian is 21/13 I just sat down, no reads - 2nd hand of the table.
Given that I flat called preflop - what is the best way to play the following streets - should I be reraising the flop, or is check/call a better line a lot of the time to get a small bluff on the river sometimes and keep the pot small?