Fold AA after this flop? (200NL 6-max)

BB is 21/9.5/0.57 over 50 hands.

Party Poker No-Limit Hold'em, $ BB (6 max, 5 handed) converter

SB ($544.95)
BB ($188)
Hero ($200)
MP ($151.05)
Button ($231.50)

Preflop: Hero is UTG with A[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $1.
<font color="#CC3333">Hero raises to $7</font>, <font color="#666666">3 folds</font>, BB calls $5.

Flop: ($15) 4[img]/images/graemlins/heart.gif[/img], Q[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $15</font>, <font color="#CC3333">BB raises to $30</font>, Hero folds.

Final Pot: $60

What does this check/min raise mean? Should I be worried about him having a queen here? Am I playing too weak tight?