im pregnant with my ex baby he says it isnt his if i dont put him on birth certificate can i still take him court for child support?

The simply answer is yes. Once the child is born you can file a paternity petition in family court. If the child is determined his , either by consent or a  DNA test then liability ensues for support. If your ex boyfriend signs an acknowledgement of paternity and his name is put on the birth certificate this is another way  that he will be liable to support the child.