New at table, so no reads. Do you fold here. Too weak?

PokerStars No-Limit Hold'em, $0.10 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Hero ($105.00)
MP ($166.00)
Button ($34.50)
SB ($116.00)
BB ($94.50)

Preflop: Hero is UTG with J, J.
Hero raises to $4, 2 folds, SB calls $3.50, 1 fold.

Flop: ($9) 9, T, 7 (2 players)
SB checks, Hero bets $7, SB raises to $21, Hero calls $14.

Turn: ($51) 5 (2 players)
SB bets $31, Hero folds.