Weak Ace vs unknown!

[irishpint]

Villian is an unknown. His raise I usually assume is a strong ace and was planning on check/folding unimproved the turn. when i hit my 2 pair i get excited...but so it he. The river is a possible flush and when raised i couldnt bring myself to reraise. how do you play this hand from the beginning. Thanks. BTW...good check raise on turn??

Party Poker 0.5/1 Hold'em (9 handed) converter

Preflop: Hero is BB with 3[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img].
UTG calls, <font color="#666666">3 folds</font>, MP3 calls, <font color="#666666">2 folds</font>, SB completes, Hero checks.

Flop: (4 SB) T[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG raises</font>, MP3 folds, SB folds, Hero calls.

Turn: (4 BB) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">UTG bets</font>, <font color="#CC3333">Hero raises</font>, <font color="#CC3333">UTG 3-bets</font>, <font color="#CC3333">Hero caps</font>, UTG calls.

River: (12 BB) 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG raises</font>, Hero calls.

Final Pot: 16 BB