DNA Test or Not

Need some input.....So the story is too long for me to go into a lot of detail but bottom line should I go behind my boyfriends back and try to make this girl who claims her baby is his get a DNA test with my daughter that's his? (This would be the second time trying to get her to do it btw) Or bring it up to him again and see if he will do it again? Or stay out of it?(which I prob won't do at all lol)