pot odds and raising on the turn

I have a question on pot odds and when it is OK to raise.

This is the hand that sparked the question:

I'm playing a 10 player limit ring game. I'm Cut Off Man and get delt Ah Ks. "Big Stick," I think to myself. "Not bad" (Although to REALLY be Big Stick AK has to be suited.) There are four callers when it gets around to me. I raise, and the Dealer folds. One of the callers also folds but the other three call.

The Flop comes 4h Th 8h. "Holy Macaroni! I've got the nut flush draw!" [img]/images/graemlins/shocked.gif[/img]

The first player bets and the other two call. Now it's to me with 12 small bets in the pot.

I think to myself that the odds of making a flush draw, Flop to River, are ~2:1 and the pot is giving me 12:1. Then I think if I raise here, I'm still getting 6:1 pot odds, way better than the odds of hitting my flush. I raise and all three other players call.

Was this a mistake here? I'm thinking about it and thinking about it, and I think I'm OK so far.

Turn comes 3s. It's big bet time now. First player bets and the other two call. I'm looking at 4:1 to hit my flush on the River. A call will give me 11:1 pot odds. I should call, no brainer right?

I start thinking that a raise here will give me 5.5:1 pot odds, still better than my 4:1 drawing odds. Should I call or should I raise?

As I'm thinking this I'm not sure if raising the right move. Then I look at that Ace of Hearts in my pocket, I hear a sexy voice whisper in my ear "Nut Flush" and I raise.

Was this a mistake? In my head I was thinking that anyone with a heart was also drawing to a flush, but I had the ace. Sure there were two straight draws on the table, but I was drawing to a flush, not a straight.

Anyway, I raise and all three other players call. The pot is getting huge.

River came 2d. No flush for me. [img]/images/graemlins/frown.gif[/img] First player checked, the next folded and the guy to my left bet. He showed Ad 5h, and ended up taking the pot with a 5-high straight. A 5-high straight... That's also know as the "idiot straight." A friggin' idiot straight!

Anyway, I've run that hand over and over in my mind (and my nightmares) and I keep thinking that, if I had to play that hand 100 times, I'd play it the exact same way pre-flop, post flop and post turn. My only question was calculating the pot odds based on a raise rather than a call. Was that a mistake or not?