Could i get some kind of food poisening (cant spell it) from out of date chicken that was frozen?

it was dated the 16 nov and was frozen until yesterday thawed and i ate it today it was dodgy cheap prossecced chicken strips from marks and spensor with fajita spice added to it. i ate it 21/2 hours ago i now have a growing cramp in my stomach as does two of my house mates who also ate it!? what could it be. ? what should i do to calm my stomach.? any advice?