Paternity was established when you completed the acknowledgment of paternity form and were placed on the child's birth certificate as her father. It was reaffirmed when the support and custody order was entered.
To the extent that a court does not regard you as estopped from disputing paternity by virtue of the prior custody/support case, even if DNA testing disproves paternity the court can nonetheless deny any motion to disestablish paternity based upon the best interests of the child. In the absence of somebody else who is prepared to step up to the plate as father, be it the actual biological father or stepparent adoption, I would view your case as a long-shot. If you are considering trying to disestablish your paternity I suggest discussing your situation in detail with a family lawyer.

