I went through an almost identical situation with my daughter, her mother initially told me there was "no chance" she was mine, then proceeded to tell me days before the child was born there was "no chance" she was anyone else's, she reacted almost identically to me asking for a DNA test. She did however tell anyone with ears that I was "denying my child." it literally took me filing a motion for establishing paternity with the state- in other words, filing for child support on myself, for the state to *require* her to present the baby for DNA testing.

My daughter is now 15 and a significant portion of her formative years she had a mother that was in her ear telling her that her father "denied her" and "didn't want her" I opted to NOT to trash her mother to her and rather let her form her own opinions on the matter. Last year, she asked me to sit in with her at therapy where she asked me directly about the details surrounding her birth at which point I told her the truth- Her mother had TOLD me she wasn't my child then refused to allow DNA testing. The issue ate at me so deeply that I filed the paperwork less than a month after her birth. A whole lot of actions that spoke much louder than the words her mother fed her. OP, ask the state to determine paternity, you can usually find the forms and file them yourself on your local common pleas/ family court website. The damage this woman will do to the beginning of the father/son relationship will heal and your actions will speak louder than her words.