My 5 year old has been suspended from preschool...need some advice please?

My son goes to preschool and has been doing so good all year. The last month the teacher has called twice during the day saying that he will not listen or sit and just wants to run around and do what he wants to do. I have tried taking things away, everything I can think of. Well this week his teacher called and said he cannot come back until Monday and that if she has to call one more time he is kicked out. Graduation is only a month away and I would love to see him make it. He is pretty behaved at home...I have ran out of things to try to get him to stop misbehaving in school. None of my other children has ever been in trouble at school so this is new. Any advice you could give would help so much.