Is my child being bullied?

My son is 12 and is in the middle of high school. He has 1 friend, which is fine with me actleast he has someone to hang around at school with. He lost that friend and hangs around in the school library, which is ok because he reads. He loves to read! But last week he started to come home every night with more and more bruises and cuts. I asked where he was getting them from, he said he was just falling over. But is it normal every night to have cuts and bruises?