$25nl full ring what to do on river?

[pearo780]

PokerStars No-Limit Hold'em, $0.25 BB (7 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

Button ($25)
SB ($28)
BB ($23)
UTG ($21.25)
Hero (MP1) ($27.75)
MP2 ($18.05)
CO ($31.45)

Preflop: Hero is MP1 with A, K
UTG calls $0.25, Hero bets $1.25, 3 folds, SB calls $1.15, 1 fold, UTG calls $1

Flop: ($4) A, A, 7 (3 players)
SB checks, UTG checks, Hero bets $3.25, SB calls $3.25, 1 fold

Turn: ($10.50) Q (2 players)
SB checks, Hero bets $7, SB calls $7

River: ($24.50) 9 (2 players)
SB checks, Hero ??

No real reads on the SB as I just sat down. Flop and turn im just building a pot and making a flush draw pay but on the river should I check behind? I can see someone check calling with a flush on the river cause of the paired board. But they could call a shove with a queen or worse ace? Am I losing value by checking behind?