Ok this is my first time with this sort of thing but I need help my ex finance has a baby that looks exactly like me and she keeps telling me that he is not mine I want to do a Dna test where she can't say no so I can figure this out where do I go for something like this

Is there a current legal father of the child? If not then go to court and ask for visitation of the child stating you believe the child is yours. Ask for DNA at that time to ensure your rights.

It would help to know your general locale so we can check the applicable laws. But the bottom line is you go to your local Family Court and petition the court for at least joint legal custody.

The easiest and best way, hire an attorney and ask for a DNA test though court. If you were having sex with her during the proper time frame it is possible and that is what you use for purpose and reason of test. The fact he looks like you has little to do with it. Honestly often we see what we want to see and in other times it just happens. I use my adopted son, everyone says he looks more like me, than my other 4 natural sons.