PokerStars - $0.10 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4: http://www.pokertracker.com

Hero (MP): 119.4 BB
CO: 208.3 BB (VPIP: 29.46, PFR: 25.89, 3Bet Preflop: 12.77, Hands: 113)
BTN: 132.4 BB (VPIP: 22.83, PFR: 17.39, 3Bet Preflop: 11.27, Hands: 193)
SB: 118.1 BB (VPIP: 45.56, PFR: 22.22, 3Bet Preflop: 4.65, Hands: 90)
BB: 86.6 BB (VPIP: 38.89, PFR: 13.89, 3Bet Preflop: 0.00, Hands: 36)
UTG: 100 BB (VPIP: 25.16, PFR: 20.34, 3Bet Preflop: 8.12, Hands: 657)

SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has Qd Ac
fold, Hero raises to 3 BB, fold, fold, SB calls 2.5 BB, fold

Flop : (7 BB, 2 players) 7s 9c As
SB checks, Hero bets 4 BB, SB calls 4 BB

Turn : (15 BB, 2 players) Qh
SB checks, Hero bets 9 BB, SB calls 9 BB

River : (33 BB, 2 players) Kh
SB bets 30 BB, Hero???

What are your thoughts on what I should do on the river? Is SB ever bluffing in this spot? What's in SB's value range?