Been married 8 yrs, had one night stand through alcohol and depression, husband knows all this. Found out I was pregnant. Husband insisted on keeping child, he loves child, and child loves him. Split 3 yrs later. Husband sees child every weekend. They dote on each other, but he refuses to pay child support, saying well you know child isn't mine, but he still insists on being daddy. Where do I stand?

If you were married when child was born, normally legally the child is his.

If he signed the birth certificate, legally the child is his.

So, what? If he does not want to pay child support , many men do not want to pay child support, you file in court, for child support, Then it will depend on your state law ( if in US) In many areas, he may not even have a right to contest. If he does, he can ask for a DNA test.

So you get an attorney file for divorce, and file for child support

OP and her husband are still married but separated?

he refuses to pay child support

Excuse me, but where do you or he think he can do that? If he is not paying support that tells me that YOU are letting him get away with it. That YOU did not ask for support in the divorce or have not taken him to court to enforce a support order.

As noted, in every US state, when a child is born to a married couple, the husband is presumed to be the father and IS the legal father unless a court rules otherwise. Depending on where you are (any question on law needs to include your general locale as laws vary by area) it may even be too late for him to challenge paternity. Even if its not, give the circumstances, I doubt if a court would not reinforce his legal paternity.

So you need to get off the stick and take him to court and force him to pay support. And, if he does decide to challenge paternity to avoid support, if it turns out he's not the father, he may lose visitation.

File for child support. Let the court decides.