Call-Down mode too early?

[Eeegah]

SB is a maniac; no significant reads on anyone else.

PokerStars 0.25/0.50 Hold'em (10 handed) converter

Preflop: Hero is MP3 with A[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">MP1 raises</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">2 folds</font>, SB calls, <font color="#CC3333">BB caps</font>, MP1 calls, Hero calls, SB calls.

Flop: (16 SB) Q[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">BB bets</font>, MP1 calls, <font color="#CC3333">Hero raises</font>, SB calls, <font color="#CC3333">BB 3-bets</font>, MP1 calls, Hero calls, SB calls.

Turn: (14 BB) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">BB bets</font>, MP1 calls, Hero calls, SB calls.

River: (18 BB) 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">BB bets</font>, MP1 calls, Hero calls, SB folds.

Final Pot: 21 BB

A great board if it weren't for the preflop 3-bet. MP1 isn't a concern as he didn't raise the flop, but BB is. I'm ahead of KK, TT and AK, but don't know what else he'd be willing to 3-bet from BB. A raise on the turn would probably force out SB and MP1 when they each face two big bets cold, but I don't see either of them as a severe threat and don't really mind them sweetening my pot. Should I have capped the flop and fired away at the turn anyway?