I always get myself stuck in situations like this where I see a free flop and decide to just go with it.

Ultimate Bet Pot-Limit Omaha High, $.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

Button ($47.10)
SB ($16.75)
Hero ($207.90)
UTG ($29.05)
MP ($49.55)
CO ($10)

Preflop: Hero is BB with A, 4, 2, 9. CO posts a blind of $0.50.
UTG calls $0.50, 1 fold, CO (new player) checks, Button calls $0.50, SB completes, Hero checks.

Flop: ($2.50) 5, 3, Q (5 players)
SB bets $2.5, Hero....

Calls.

This hand isn't as strong as it seems. You have a 9 high flush draw and only 2 outs to nuts.

I just call and re evaluate on turn if i hit my straight.

Yep. If SB was deeper I wouldn't mind a small raise to potentially clear some outs.