Am i wrong for wanting my bf to get a dna.......?

My Bf and I have known each other 2yrs ...well long story short we fell out for a short period of time last year and he got hosed pregnant.....well this ex is very obsessive and has not stopped trying to get him back. They have been broken up almost 3years. Well now the baby is here we are now dating we w have been talking about moving in together but I would like for him to get a DNA test before I make that commitment. He was doubtful when she was pregnant that it was his but now the baby is here he automatically thinks its his....I'm a female and I have seen it way to many times that girls will pin a baby on a Guy to keep him around when it's in fact not his....I know there is a strong possibility she but its always that small chance....