I didn't right away. They said to wait at least a month to avoid nipple confusion. Eventually by 6 weeks I couldn't go anywhere because when he was tired he wanted to comfort nurse. Gave him the pacifier then!
My son wouldn't latch for 3 1/2 weeks. He couldn't suck properly because his jaw was crooked. I think the paci helped him learn to suck better. He hasn't had a bottle in almost a week now (was down to 1 bottle a day) and has his paci ALL the time and he breastfeeds like a champ.
The hospital I was taken to after my son was born didn't even offer one. They said they don't offer them to breastfed babies because of nipple confusion which was okay with me because I didn't want LO to have one anyways.
No, I waited a month at least before even trying to give her one.
She wouldn't take one after that, only wanted boob. But it worked out fine for us. The paci, I learned was unnecessary, and I became a human pacifier.