12 hands isn't a whole lot..

I think the river is a call, he can be v betting worse A's than yours (AK, AJ, AT) There's also probably a non zero bluffing %. I would add 22 to your range. Why don't you put some ranges into pokerstove?

I'm fine with both flatting or 3bing PF. We don't have reads so we're kinda just flying in the dark.