AJ when do you lay down top 2 pair

I have A[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/spade.gif[/img].
Limp for $1, Villain raises to $3, Button calls, BB calls, I call.

Flop: A[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/spade.gif[/img]
Pot size: $15
I lead for $10, Villain calls, everyone folds.

Turn: 3[img]/images/graemlins/club.gif[/img]
Pot size: $35
I bet $15, Villain raises to $30, I call.

River: Q[img]/images/graemlins/heart.gif[/img]
Pot size: $95
I check, Villain bets $27, I call.

Villain shows: 9[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/diamond.gif[/img].
Wins $150 with trip 9's.

Question: Did I play wrong? Should I lay down on the turn? River?