DNA Testing: I Cheated on My Husband N Got Pregnate by a Other Man

I was living in utah at the time n my husband was living in California. I hadan affair with a friend and got pregnate i came back to california to try to fix things n did not tell my husband my daughterwas his. She is now 3 months old and i am getting a divorce. I ended up telling him that my daughter is not his. He still wants to fight 50/50 custody rights. Can he even do that. But at this point i am conserned for the safty of my daughter beacuse he yells at her when he gets fusterated. I want to do a dna test n try to get his name off her birth certificate beacuse her biological father is fixing some stuff in mexico but eventually wants to enter into her life what can i do

DNA Testing: I Cheated on My Husband N Got Pregnate by a Other Man