Low pocket pair as an overpair

[Brom]

Party Poker 15/30 Hold'em (10 handed) converter

UTG is a loose passive with 36/3. CO has cold called 2 raises in the last round (this is my first round), one of those times with JTo.

Preflop: Hero is MP3 with 6[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/heart.gif[/img].
UTG calls, <font color="#666666">4 folds</font>, <font color="#CC3333">Hero raises</font>, CO calls, <font color="#666666">2 folds</font>, BB calls, UTG calls.

Flop: (8.66 SB) 3[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, UTG checks, <font color="#CC3333">Hero bets</font>, CO calls, BB folds, <font color="#CC3333">UTG raises</font>, <font color="#CC3333">Hero 3-bets</font>, CO calls, UTG calls.

Turn: (8.83 BB) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
UTG checks, <font color="#CC3333">Hero bets</font>, CO calls, UTG calls.

River: (11.83 BB) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
UTG checks, <font color="#CC3333">Hero bets</font>, CO calls, UTG folds.

Final Pot: 13.83 BB

My read is that both of them are on the flush draw (I decide this after the turn bet), thoughts? Overplayed maybe?