$0.02 NL FAST (6 max) - Holdem - 6 players

BTN: 40 BB
Hero (SB): 57 BB
BB: 101 BB
UTG: 156.5 BB
MP: 72 BB
CO: 258 BB

Hero posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has 9♠ 9♦

fold, fold, CO raises to 3 BB, fold, Hero calls 2.5 BB, fold

Flop: (7 BB, 2 players) Q♣ Q♦ 3♦
Hero checks, CO bets 2 BB, Hero calls 2 BB

Turn: (11 BB, 2 players) K♥
Hero checks, CO bets 5.5 BB, fold

CO wins 10.5 BB

Afterwards I analysed this hand again. Saw that I had 71% equity against my opponent. Should I made the call? Or did this guy had a K?

I think your fold is fine. Once the K hits and he sizes his bet up, you'll probably have to call a river bet too.

You could have considered 3 betting his open preflop.

I think you've noticed how your opponent's bid has changed. You would have to make an even more difficult decision on the river, as the opponent's stakes only increased. If there was no flush draw on the flop, then I check-raise sometimes in such cases. This shows the strength of the hand and some players discard the ace high or king high. In this case, I would do the same as you.

I probably would have done the same, but you have to understand that HUD showed this opponent if VPIP 15-25%, then fold is definitely the right decision, and if it was a maniac, even if you had pushed, he would have called.

Thumb rule: don`t hit set - fold. Calling small cbet OK sometimes.