Yes, you can certainly request that a genetic test be done. The formal legal action for you would be a Petition for Legitimation, since you believe that you are the father of a child born out of wedlock. Only a mother can file a Petition for Paternity.
If your ex-girlfriend agrees to provide DNA from the child, then the test can take up to 14 days to get back depending on the testing lab that you use. You can expect to pay approximately $80 - $150 for the test to be done. If the test results come back positive and you are in fact the legal father of the child, then you will need to either negotiate a parenting plan with your ex-girlfriend that includes child support and parenting time for you, or you will need to seek a parenting plan in Court.
Do you know if your ex will allow for the genetic testing to be done? If she will not cooperate, then you will need to file the Petition for Legitimation in Court and request that the Court Order genetic testing. An attorney can help you file all of the appropriate paperwork.
Depending on whether or not she cooperates your costs can vary. It would be cheaper and easier if she cooperates. If you have to go through the Courts to seek an Order to compel her to take the DNA test, then this can take longer and cost more.
I suggest you contact an attorney for a free consultation to get some more specific information about your best strategy in moving forward, and that the specific costs would be for you.
You can file a Petition for Legitimation in the county superior court where your ex-girlfriend lives. If she denies you are the biological father, you can ask the court to require a paternity test. If it comes back positive that you are the child's father, then the court will enter in your favor and you will be deemed the legal father. With that comes the responsibility of child support. As far as cost, the filing of a petition in most jurisdictions is approximately $80 to $95 and the paternity test will be another $100 to 150. If you retain an attorney to help you, the cost of this action will obviously be higher and will depend upon that attorneys' rates.
This answer was provided for informational purposes only. If you want more specific information, then you should call one of the qualified attorneys on Avvo to help you.
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