How can I get the child support if the father is denying that he is the father?

You don't need a paternity test in order to file for and receive child support. You should retain the services of an experienced attorney. It would be the father's responsibility to contest paternity, if that is his desire. However, the court can go forward and order child support until such a time that he is proven not to be the biological father of your child. Retain an attorney to handle this for you.