I was a little nervous about my cousins pitt bull and my grandma's other dogs. When I brought my little man over to visit, they brought Skye, the Pitt bull, out by herself to see him. They made her sit still and gave her love while I let her sniff him. After that, she'd go to the base of his carseat when he was napping and laid down next to him. Dogs understand newborns very well. Just make sure they get plenty of attention and let them get to know the maybe in a way that makes you feel comfortable with the situation.
Dogs love babies they might be very protective or keep there distance. My friend has 2 pit bulls and they are so loving even tho I was 5 weeks at the time they knew. One of them used to ignore me and now he played right next to my belly and just stayed there lol I'm now 15 weeks and they still act the same way. They will sniff your baby lol