回複：Not True

The child's biology father is responsible to pay child support even if you got married later with other man.

You should negitiate with him to settle this without filing a lawsuit that cost a lot on both sides. But if cannot reach an agreement, you may goto court (goverment may provide free lawyer for you) to settle this. To do that you must know his name, address and other information , so that the court may notify him of the lawsuit