How should I play small pocket pairs (22-99) on Big Blind readless vs a minraise?

Should I shove or flat? I don't think that folding or 3betting not all in is an option.



PokerStars - $6.85+$0.15|10/20 NL (2 max) - Holdem - 2 players

SB: 500

Hero (BB): 500

SB posts SB 10, Hero posts BB 20

Pre Flop: (pot: 30) Hero has 2 2 

SB raises to 40, Hero?