He had a affair and got the other woman pregnant.she has two children from a previous marriage.these children live with their father.this woman lives with her mother and sister.the grandmother is a drug addict.can you please tell me what rights my husband has.we live in California.thank you

Once the child is born, he can file in court for a DNA test ( most likely she will anyway) once he is proven the father, he can file for custody or joint custody Or he can request visitationif he does not want custody.

And of course if she gets custody he will be told the amount of child support he will have to pay.

But until the baby is born there is not a lot he can do