I'm weak - ace + flush draw

[cbloom]

I'm weak part one. Villains are pretty average players. I'm getting great odds to call to the flush. When the J hits the river it looks to me like trips, so I'm gone. Do I need to check-raise the turn here? Their small bet looks weak for sure, but I thought I'd just take my good odds and just call.

Party Poker No-Limit Hold'em, $ BB (9 handed)
MP3 ($53.37)
CO ($109.35)
Button ($109.40)
Hero ($100.65)
BB ($80)
UTG ($159.70)
UTG+1 ($113.15)
MP1 ($121.96)
MP2 ($131.20)

Preflop: Hero is SB with 7[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/spade.gif[/img]. Hero posts a blind of $0.50.
<font color="#666666">2 folds</font>, MP1 calls $1, <font color="#666666">1 fold</font>, MP3 calls $1, CO calls $1, <font color="#666666">1 fold</font>, Hero (poster) completes, BB checks.

Flop: ($5) 5[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
Hero checks, BB checks, MP1 checks, <font color="#CC3333">MP3 bets $4</font>, CO calls $4, Hero calls $4, BB folds, MP1 folds.

Turn: ($17) A[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">MP3 bets $5</font>, CO calls $5, Hero calls $5.

River: ($32) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, MP3 checks, <font color="#CC3333">CO bets $15</font>, Hero folds, MP3 folds.

Final Pot: $47