Why Is My Husband Hiding Paternity Doubts About Emma?

So my sister in law slipped in a conversation where she said no one believed me when I said I was pregnant with Emma! (I had 2 misscarages before I got pregnant with her but didn't tell anyone) so since me and my husband were rocky during the time of me getting pregnant that's Wat Im assuming she's talking about, so fast forward to yesterday my husband says "whoever said she isn't mine is full of It" and i was thinking and thinking so I finally asked him who's saying stuff and he said no one and I don't believe him so I told him please tell them I'll pay for a fuken DNA test and I'll laugh at them/him or her in there fuken faces.... So I'm mad cuz he won't say