Flopped mid pair on drawish board against unknown

[sharpie]

Am I playing this like a limit player?

Poker Stars
No Limit Holdem Ring game
Blinds: $0.25/$0.50
4 players
Converter (http://www.neildewhurst.com/hand-converter)

Stack sizes:
UTG: $52.75
Button: $118.60
SB: $70.30
Hero: $50

Pre-flop: (4 players) Hero is BB with 5/images/graemlins/club.gif 7/images/graemlins/heart.gif
UTG folds, Button calls, SB folds, Hero checks.

Flop: 2/images/graemlins/club.gif 9/images/graemlins/heart.gif 7/images/graemlins/club.gif ($1.25, 2 players)
<font color="#cc0000">Hero bets $0.8</font>, Button calls.

Turn: A/images/graemlins/diamond.gif ($2.85, 2 players)
<font color="#cc0000">Hero bets $2.2</font>, Button calls.

River: 4/images/graemlins/heart.gif ($7.25, 2 players)
Hero checks, <font color="#cc0000">Button bets $2.5</font>, Hero calls.