Pound all the way?

[Poker_Ink]

Euro 3/6 6 max, 5 handed.

I am button with 9 [img]/images/graemlins/spade.gif[/img]9 [img]/images/graemlins/club.gif[/img]

Folded to me, I raise, SB calls, BB folds. I have no reads, or stats.

Flop is 9: diamond:5 [img]/images/graemlins/spade.gif[/img]2 [img]/images/graemlins/club.gif[/img]
SB checks, I bet, SB calls.

Turn is: Q [img]/images/graemlins/heart.gif[/img]

SB checks, I check.

I don't know if this was stupid or not. However, I had the feeling of one of the following: either SB had two over cards, and would fold when missing the turn. And if he hits the river, he will bet and I can raise to get another bet. Or, he has an underpair, and will fold the turn, or bet the river when I check and get the same extra bet with my raise.

Is this just dumb thinking?