Please don't respond anymore I'm on wrong site as I live in UK. Thanks to all those who did though

One thing I can say is you should still go for the paternity test and do not sign anything with CSA until you are proven to be the father. Although I think some states require you to pay simply because you signed the birth certificate.
You say they never got back to you and you can not have children so that is two things I think would indicate that you may not be the father. If you have to pay it is ordered what you have to pay and goes to the mother or the state. Also they most probably would go back to when she originally filed or when he was born and go after you for a lot of back support. If you pay child support you should have a right to joint custody and visitations since they are saying you are the father, I would think.
If he is not your son and you end up not having to pay child support if you still want him in your life you can give HIM whatever money you want when you want and let him know you want to be a father figure in his life.

What state are you in? Some of what you need to know depends completely on the state.

I live in England. I think I'm on the wrong site...

Oh not sure about how England handles this but you should check all your options and see if you can get anywhere with paternity testing.

Thread closed,

In your original post, the more info you give the better answers you will get.

Also you will get in time a lot of UK experts but you have to leave your post up for several days, experts here do this in their own time and are not paid, so some only check the boards every few days, so after a week or two you will get much better answers.

But since you did not leave you original post up, I will close the thread