Can I fold this, good hand?, good pot

Villian is 20/0/1.9, I have about 50 hands with opponent, he hadn't done anything noteworthy.

I'm figuring at the point of me calling the check/raise on the flop at worse I have effective odds of 7 to 2.5 on calling down. But I figure most of the time I'm behind here and I've got the risk of the flush draw hitting.

It seems unlikely the check/raiser was a worse hand, although it's possible he's value raising a flush draw.

Party Poker 2/4 Hold'em (9 handed) FTR converter on zerodivide.cx

Preflop: Hero is BB with 3[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/club.gif[/img].
UTG calls, <font color="#666666">1 fold</font>, <font color="#CC3333">MP1 raises</font>, <font color="#666666">2 folds</font>, CO calls, <font color="#666666">1 fold</font>, SB calls, Hero calls, UTG calls.

Flop: (10 SB) 6[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, <font color="#CC3333">Hero bets</font>, UTG folds, MP1 calls, CO calls, <font color="#CC3333">SB raises</font>, Hero calls, MP1 folds, CO calls.

Turn: (8.50 BB) Q[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">SB bets</font>, Hero calls, CO calls.

River: (11.50 BB) 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">SB bets</font>, Hero calls, CO folds.

Final Pot: 13.50 BB