100 NL, JJ re-raised pot, playing for stacks again.

[SABR42]

Don't have reads yet. I'm new to the FTP 100 NL game (previously played 100 NL on Stars only) so I don't really know anyone yet (it sucks).

Full Tilt Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 7 Players - (LegoPoker HH Converter)

SB: $130.95
BB: $165.40
UTG: $76.30
UTG+1: $47.40
MP: $96.00
Hero (CO): $103.75
BTN: $98.15

Preflop: Hero is dealt J[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/heart.gif[/img] (7 Players)
2 folds, <font color="red">MP raises to $3.00</font>, <font color="red">Hero raises to $10.50</font>, 3 folds, MP calls $7.50

Flop: ($22.50) 2[img]/images/graemlins/spade.gif[/img] 4[img]/images/graemlins/heart.gif[/img] 2[img]/images/graemlins/club.gif[/img] (2 Players)
MP checks, Hero checks

Turn: ($22.50) 7[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">MP bets $21.00</font>, Hero calls $21.00

River: ($64.50) T[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">MP bets all-in for $64.50</font>, Hero calls $64.50

I decided to check the flop because I wasn't sure if I wanted to call a check-raise push on the flop. Decided to wait for the turn to make a decision.

Turn call is standard I think. No way I can fold there, and I don't want to raise either.

Should I call river? I feel my hand is underrepped because he'd expect me to bet the flop with an overpair, but I didn't.

Is he bluffing here often enough? Something like A [img]/images/graemlins/heart.gif[/img]K [img]/images/graemlins/heart.gif[/img] would make a lot of sense.