[SH] NL50 QQ turn

Prima, $0.25/$0.50 No Limit Hold'em Cash, 6 Players

Hero (BB): $51.90 (103.8 bb)
UTG: $45.46 (90.9 bb)
MP: $50.93 (101.9 bb)
CO: $81.91 (163.8 bb)
BTN: $61 (122 bb)
SB: $120.33 (240.7 bb)

Preflop: Hero is BB with Q Q
4 folds, SB raises to $1, Hero raises to $4, SB calls $3

Flop: ($8) 6 A 9 (2 players)
SB checks, Hero checks

Turn: ($8) A (2 players)
SB checks, Hero bets $4, SB raises to $8, Hero folds

Anon table.

Checkbehind turn, call/bet river?
As played, calldown? SB was unknown, but seemed fishy. After my flop checkbehind, he could know that I wont have an Ace very often, so turn is quite a good spot to bluff. On the other hand, minchRaise is not very often a bluff, as he gives me good odds to call...