Trips turn into potentially lower FH - bad river call?

[whisker]

Hello all,

This was a $1/$2 NL game at a casino. 9 players.

I am BB with about $180. Have not been forced to show a hand yet. I have a somewhat tight image, not in too many pots yet.

MP seems decent. Playing tight PF, and shows some aggression when he has something. Plays position.

I am dealt Q3, it is limped around to me with four other players in the pot.

Flop 33A.
I bet $6.
MP calls. I am putting him on an A
Everyone else folds.

Turn is an 7
I bet $15
MP calls.
I call

River is a A!! I have a boat, but he may have one now as well.
I check.
MP bets $30.
I call.



I feel I should have laid it down, but could not get away from the hand. Any thoughts on my play?