My Son (13 Year Old) Went To The Movies And

My son (13 year old) went to the movies and was eating popcorn and cracked his tooth....There is a blood line where the grooves of his told is and it looks like the tooth is caving inward. I'm not sure if it is his permanent tooth . This tooth is the second from the last molder on the bottom right side of his mouth. By this being Easter Sunday I think we may have to wait to be seen on Monday. My fear is him swallowing his tooth before then.