Will baby pacifier harm baby face?

I have a 2 months 3 weeks old baby who would sleep if i give her her pacifier. people say that i shouldn't give it to her in the first place because she'll wanted . I really dont' care if she wanted but they sceare me by saying that her face (mouth) will be like its sore (lip) and shell have a underbite. Is that truth? Doc say that i could give it to her but after 4months i shouold stop. What do you guys think? And when did you guys stop giving your baby a pacifier?