Villian is 20/2/4 over 50 hands, but that doesn't much matter for my purposes here.

I am often lost on how I should get my money in here. I think it's most likely that villian has an ace. Since the villian is unknown, I really think I played this wrong, and I knew it as I was about to do it, but I couldn't quite figure how I'd go about the next two streets, so I just pushed.

PokerStars No-Limit Hold'em, $1.00 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG ($64.15)
UTG+1 ($25.60)
MP1 ($94.15)
MP2 ($196.05)
Hero ($160.20)
Button ($77.55)
SB ($11.65)
BB ($49.50)

Preflop: Hero is CO with 9, 9.
4 folds, Hero raises to $4, Button calls $4, 2 folds.

Flop: ($9.50) K, 9, A (2 players)
Hero bets $9, Button raises to $18, Hero raises to $156.2...

So what are you thinking to do after villian minraises?