I got smacked in the face by accident and i think my contact fell out. how would i know for sure? my eye was irritated and watery when it happened

Check vision: Compare the vision in the non-smacked eye with that in the one that got hit. If the eye that got hit is otherwise normal (no redness, no internal bleeding, no structural damage) then the vision will be normal if the lens is in place and blurred if not. However it might be blurred if there is damage. If the blur persists see your ophthalmologist.