NL5 SH: shaky overpair vs. river shove

Hello.
I had been playing at this table only for abt 10 hands, therefore I haven't got any reads, other than that he pushed river very quickly.

PokerStars No-Limit Hold'em, $0.05 BB (4 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($4.99)
SB ($4.73)
BB ($6.17)
UTG ($5.15)

Preflop: Hero is Button with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $0.2</font>, <font color="#666666">1 fold</font>, BB calls $0.15.

Flop: ($0.42) 3[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $0.32</font>, BB calls $0.32.

Turn: ($1.06) 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $0.7</font>, BB calls $0.70.

River: ($2.46) 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets $4.05</font>, Hero???

Should i bet more on the flop and turn in situations(draws) like that? This was my usual size for C-Bets.

I've played quite a bit at these micro-stakes, and have recognised that people overbet or push all-in with very strong hands, such as top-2, sets etc, even on the flop, much more often than in the past. Then again, there are some busted draws, the 3 is a 'scare-card', and the possibilty that thinks that I have AK or something, but why overbet the pot?

Thx.