Party Poker No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Hero ($56.50)
UTG ($100.60)
UTG+1 ($26.35)
MP1 ($7.75)
MP2 ($9.50)
MP3 ($10)
CO ($10.70)
Button ($54.35)
SB ($37.95)

Preflop: Hero is BB with Q, Q.
UTG raises to $2, 6 folds, SB calls $1.75, Hero raises to $5.75, UTG calls $4, SB calls $4.

Flop: ($18) K, A, 8 (3 players)
SB checks, Hero checks, UTG checks.

Turn: ($18) 6 (3 players)
SB checks, Hero checks, UTG checks.

River: ($18) 4 (3 players)
SB checks, Hero ??

Is it worth a bet here or should I just try check it down?