My wife and I had been dating approx 9 months when she became pregnant. She said the baby was definitely mine, so we got married. We have been married 7.5 years. We began discussing separation earlier this year and it was soon decided that was the direction she wanted to go. With the marriage being over I decided to go ahead and get a paternity test on the child due to doubts I had. It turns out that he is not mine.

I would like to stay in the childs life but have issues signing a contract to pay his mother child support, can I retain fathers rights and just support him directly? Is there another route to go? She does know who the father is, but says he does not know. Does this classify as paternity fraud? if it does what does it do for me?

She claims that she did not know the child was not mine but had doubts when he was approx 2years old. Her lawyer is saying that this relieves her from paternity fraud. I am having a difficult time accepting that this would fly going thru the court system, but I have read some horrible cases involving paternity issues with fathers. Is this a viable excuse?

Being duped into marrying her, I have supported her and her other 2 children from another marriage that she receives very little child support from [2000/year] because the father does not pay and she does not make enough to support them without her family support. I paid off substantial debt from her previous marriage. I have bought a bigger house do to the size of the family, that I am stuck with. Am I entitled to any reimbursement for what she has done, if not in the divorce hearing in a civil suit? Would this classify as an economical hardship caused by her marital misconduct and be considered in the property distribution?

Until a judicial determination of paternity is made ( a court acknowledging the results of the paternity test) the child is still presumptively yours under the law as he was born to you as husband and wife. Once the matter of paternity has been adjudicated and you are found not to be the father, you have no rights to the child.
With respect to your other questions regarding paternity fraud, if she believed the child to be yours, she has not committed fraud, or martial misconduct that would lead to an unequal distribution of assets.

If she had slept with 2 different people while she was ovulating how could she, a 30+ year old woman with 2 kids, believe without a doubt that I was the father and the other was not without getting a test done. Would she not be negligent of making a mature decision?

I know of no claim for negligence in this context. I am truly sorry for the pain she has caused you, and the child.