AJo button - confused with a gutshot

[Fiddler]

Hadn't been there long so reads on anyone. Yeah, newbie alert on the questions.

Party Poker 1/2 Hold'em (6 max, 4 handed)

Preflop: Hero is Button with J/images/graemlins/heart.gif, A/images/graemlins/spade.gif.
<font color="CC3333">UTG raises</font>, <font color="CC3333">Hero 3-bets</font>, SB calls, <font color="CC3333">UTG caps</font>, Hero calls, SB calls.

3-bet ok?

Flop: (13 SB) 3/images/graemlins/spade.gif, T/images/graemlins/diamond.gif, K/images/graemlins/club.gif <font color="blue">(4 players)</font>
SB checks, <font color="CC3333">UTG bets</font>, Hero calls, SB calls.

This felt wrong... I was thinking about raising and seeing how SB and UTG would respond... but chickened out. How would that be? Seems like SB cold-calling and/or UTG reraising would be pretty bad but it would give me some indication of what they have.

Turn: (8 BB) 3/images/graemlins/club.gif <font color="blue">(4 players)</font>
SB checks, <font color="CC3333">UTG bets</font>, Hero calls, SB calls.

I don't know why I'm calling... bleh.

River: (11 BB) 5/images/graemlins/diamond.gif <font color="blue">(4 players)</font>
SB checks, UTG checks, Hero checks.

Final Pot: 11 BB

[spydog]

Preflop: 3-bet is OK if raiser has low raising standards. If they have a PFR% of 8 or less, I usually muck.

Flop: Calling here is good. You could raise here to get a free ride to showdown.

Turn: Calling is OK, but folding wouldn't be bad. You could spew an awful lot of chips if you are up against a boat, but that's doubtful. I probably call and hope my queen hits.

River: Fine.