Yeah, your almost certainly behind and the odds arn't there. Also you have 2 players call a raise and a reraise on that flop, I think it's a safe assumption that one of them was chasing either a flush or a straight and the turn completed both. Why not take a free shot at the boat? This is the biggest advantage of position and as you will be last to act on the river you can still controll the size of the pot (call a small bet if you don't fill, raise if you do)