AKo Shorthanded - too timid?

[FA_man]

2/4 shorthanded (4-way) game online im in the SB with AdKh.

UTG (or is he the CO?) folds...
Button raises, I reraise, BB folds, button caps
Heads up on the flop me and button for 9SB

5c5s7c

I check, he bets, I checkraise, he calls

(5c5s7c)Jc

check check

(5c5s7cJc)2h

check check


My hand was good. Now in retrospect I think i may have missed the turn bet. At the time I was afraid of a raise. When the river came, I figured if he didnt have me beat he wouldnt call, so i just checked... what do you guys think?

Thanks
FA