Confused by turn raise

[Russ McGinley]

No read on villain. Also no definitive reason why I limped instead of raised.

Party Poker 3/6 Hold'em (10 handed) converter

Preflop: Hero is UTG with K[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/diamond.gif[/img].
Hero calls, UTG+1 calls, <font color="#666666">6 folds</font>, SB completes, BB checks.

Flop: (4 SB) 8[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, BB checks, <font color="#CC3333">Hero bets</font>, UTG+1 calls, SB folds, BB folds.

Turn: (3 BB) Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG+1 raises</font>, Hero calls.

Admittedly I feared the worst here and just called. When the flop came, for whatever reason I thought that somebody had a set of 6's.

River: (7 BB) 8[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">UTG+1 bets</font>, Hero calls.

Does this river worry anyone?

Final Pot: 9 BB

Afterwards I feel I played this very weakly. This was my first real test in 3/6, as I wanted to gauge how I'd do. I played my normal game mostly but did not get much to work with.