Villain was unknown just sat down only two hands one he 3 bet and won...

Merge Network $0.02/$0.04 No Limit Hold'em - 8 players -
BB: $4.00
UTG: $8.29
Hero (UTG+1): $6.69
MP1: $4.66
MP2: $5.32
CO: $4.28
BTN: $0.80
SB: $4.17

Pre Flop: ($0.06) Hero is UTG+1 with J A
1 fold, Hero raises to $0.20, 4 folds, SB calls $0.18, 1 fold

Flop: ($0.44) 2 7 A (2 players)
SB checks, Hero bets $0.33, SB calls $0.33

Turn: ($1.10) 6 (2 players)
SB checks, Hero bets $0.82, SB calls $0.82

River: ($2.74) 4 (2 players)
SB bets $2.00, Hero ??

I folded b/c of the bet and flush... does the rest look good flop and turn sizing? Also you guys norm playing this hand in this pos??