Bottom Pair, Heads Up, Donking the Turn?

[joker 77]

Poker Stars
Limit Holdem Ring game
Limit: $0.25/$0.5
10 players
Converter

Pre-flop: (10 players) Hero is SB with 2[img]/images/graemlins/spade.gif[/img] 2[img]/images/graemlins/heart.gif[/img]
8 folds, <font color="#cc0000">Hero raises</font>, BB calls.

Flop: 9[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/club.gif[/img] (4SB, 2 players)
<font color="#cc0000">Hero bets</font>, BB calls.

Turn: 5[img]/images/graemlins/heart.gif[/img] (3BB, 2 players)
<font color="#cc0000">Hero bets</font>, BB calls.

River: 6[img]/images/graemlins/heart.gif[/img] (5BB, 2 players)
Hero checks, BB checks.

Results:
Final pot: 5BB

Was it a mistake to donk the Turn?