Jacks

Opp. is 21/7/2 after 100 hands atm. I was really confused on the turn. Should I just shove it?

PokerStars No-Limit Hold'em, $1.00 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG ($110.75)
UTG+1 ($98.90)
MP1 ($99)
MP2 ($105.05)
MP3 ($158.10)
Hero ($60)
Button ($127.15)
SB ($44.70)
BB ($125.10)

Preflop: Hero is CO with J, J.
UTG calls $1, 1 fold, MP1 calls $1, 2 folds, Hero raises to $6, 3 folds, UTG calls $5, MP1 folds.

Flop: ($14.50) 4, 6, 5 (2 players)
UTG checks, Hero bets $13, UTG calls $13.

Turn: ($40.50) Q (2 players)
UTG checks, Hero...

Of course this will be read dependent. But the Q on the turn shouldn't scare you at all. If you've seen him slowplay sets or limp with QQ-AA preflop then beware, otherwise the likeliest holding by villain is 77, maybe 33 or 88.

I check behind because my hand has showdown value but isn't that great anymore.

I like checking behind here as well because it becomes more unlikely that he'll call your bet with a worse hand whereas if you check he can bluff the river or he can make a hero call with 3rd pair etc.. after sensing your 'weakness' on the turn.

Bet 22$ on a non A/K river if checked to?