Villian is unkown, just sat down a couple of hands ago. Call or fold vs. unknown? I checked the river hoping to get a bluff from a missed flush draw, but thats a big bet for a bluff. Should I just lead the river with 2 pair? Also, how were the other streets played?

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

UTG ($56.55)
Hero (UTG+1) ($25)
MP1 ($5)
MP2 ($25)
CO ($41.65)
Button ($26.05)
SB ($10.10)
BB ($5)

Preflop: Hero is UTG+1 with A, J
1 fold, Hero bets $1, 3 folds, Button calls $1, 2 folds

Flop: ($2.35) A, Q, 3 (2 players)
Hero bets $1.75, Button calls $1.75

Turn: ($5.85) 9 (2 players)
Hero bets $4.25, Button calls $4.25

River: ($14.35) J (2 players)
Hero checks, Button bets $19.05 (All-In)