Introducing dogs to newborn

I’m 22 weeks pregnant and something that has been on my mind lately is how to introduce my dogs to my son when he’s born. I’m a little nervous considering they’ve never been around a baby that small, although they’re both great with kids. They’re both such sweet girls and i have no fears about them harming baby but some things you truly never know! I’m sure it’s going to be a huge adjustment for them as well, so has anyone had any luck on ways to kinda prepare their pups? I know dogs are instinctual, so i’m sure once my belly gets bigger they’ll start to realize something is going on. Just want to be as prepared as possible to have all my babies living peacefully together!