pocket sevens

[lillemkk]

multi table tournament already in the money 18 players left blinds at 3000/6000 total tournament chips 1521000. I am sitting in small blind with 7-7 with 72000 in chips. Person with 71000 in chips raise up to 12000 (double the BB) I reraise to 24000 every one folds back roun to raiser who calls my re raise. Flop comes AJ3 i check he bets 24000. Do i think he is on a steal and move in. do i call(and then maybe face a bet on the turn) or do i fold and preserve my stack. Or should i have made the bet first and represented the ace.