Could I get expelled from school for this?

Today me and 3 of my friends got found out smoking weed on the school field at dinner, it was my friend that brought it in and i didnt have much and the teachers know that, because me and all my friends were 'interviewed' after dinner at school and the deputy head teacher said hes gonna ring home on monday when he decided what our punishment is. Do you think i could get expelled even though it wasnt me that brought it in?