Hitting Himself In Arms And Legs, Become Anti-social, Very Irritable, Isolated. Is This Sign Of Schizophrenia ?

My son has been experiencing some symptoms lately that have me concerned....he is hitting himself in the arms and legs....has become anti social....walks around with his head down with a look on his face that says he is in pain. He grunts instead of communicating. He is not good in social settings. Usually just sits back and says nothing. Very irritable, can become belligerent when asked to do simple tasks. I recently divorced from my husband and I am sure he is still upset regarding this. But I think his symptoms have gone beyond just being upset. He is isolated. I looked up symptoms for schizophrenia and one of the symptoms is the flat effect. He experiences no sadness, joy, happiness or any other emotion. Could this be a sign of Schizophrenia?