NL100 strange pre Action, did not know what to do on Flop

[ComputerMaster]

No-Limit Hold'em, $1 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

BB ($122.10)
UTG ($98.15)
MP ($71.55)
CO ($109.10)
Button ($216.41)
Hero ($109.35)

Preflop: Hero is SB with 5[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/diamond.gif[/img].
<font color="#CC3333">UTG raises to $2</font>, <font color="#666666">3 folds</font>, Hero calls $1.50, <font color="#CC3333">BB raises to $4.5</font>, UTG calls $3, Hero calls $3.

Flop: ($15) J[img]/images/graemlins/spade.gif[/img], 2[img]/images/graemlins/diamond.gif[/img], 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">BB bets $5</font>, UTG folds, <font color="#CC3333">Hero raises to $15</font>, BB calls $10.

Turn: ($45) 9[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">BB bets $5</font>, Hero folds.

Final Pot: $50