[Closed] A5s $0.5/$1 FR

I had nut flush on the river. As it seemed improbable for me that someone might be drawing for FH, I just called opponent's bet to keep more players in the hand and bring in some deception. Was it ok, or should I rather raise immediately?

Hand converted with online PokerStrategy.com hand converter:

Play hand

$0.5/$1 Fixed-Limit Hold'em (10 handed)

Preflop: Hero is BU with A:c, 5:c.
UTG raises, UTG1 folds, UTG2 calls, 2 folds, MP3 calls, CO folds, Hero calls, SB calls, BB folds.

Flop: (11 SB) 9:c, A:s, J:c (5 players)
SB checks, UTG bets, UTG2 calls, MP3 calls, Hero raises, SB calls, UTG calls, UTG2 calls, MP3 calls.

Turn: (10.5 BB) T:c (5 players)
SB checks, UTG checks, UTG2 bets, MP3 folds, Hero calls, SB calls, UTG folds.

River: (13.5 BB) K:d (3 players)
SB checks, UTG2 bets, Hero raises, SB folds, UTG2 3-Bets, Hero caps, UTG2 calls.

Final Pot: 21.5 BB.