5/10 NL...Overbet?

[AggieAce]

Here's my key hand from last night. What's you're thinking here? No reads on the table, just sat. First hand I've entered the pot...

I've got $550, Villan has me covered
I'm in MP, dealt A [img]/images/graemlins/spade.gif[/img],Q [img]/images/graemlins/heart.gif[/img] folded to me
I make it $35, Villan behind me calls, everyone else folds...

Flop: A [img]/images/graemlins/diamond.gif[/img]Q [img]/images/graemlins/spade.gif[/img]9 [img]/images/graemlins/diamond.gif[/img]
I bet out $35, Villan raises to $400, Hero...

Anyone? I bet $35 on the flop because I don't want to lose AJ or KQ. Comments and advise welcome.