In my opinion young babies and young dogs don't match.
Young baby = older dog.
Older child = young dog.
You need to train the pup well long before you introduce a child into the environment so that you can control the dog around the child and ensure the safety of both of them.
A pup could see a baby as a toy or fellow pup, they 'play bite' to learn biting strength. Puppies also pounce everywhere, on everything, with little control for 6 months, and take a lot of work to train - house train , toilet train, lead train, recall. And the separation anxiety it suffers for the first few weeks is like having a newborn in itself.
Puppies are puppies till approx 2 years old. You're post reads like neither of you have had dogs before which further extends reasons not to do it now when you are about to have your first baby.
Baby will have no appreciation for this dog whatsoever and you will be run off your feet on maternity leave with constant cleaning up after both of them. Shit, sick and needing your attention. Just as baby is drifting of to sleep, puppy starts barking. You will go nuts.
Wait till baby is on his/her feet, no longer needs 'sterile' everything and old enough to understand words like yes, no, gentle, careful. Then they will love their puppy to bits and can be taught how to treat puppy properly and safely.
Young baby and young dog = neither of them have any sense.
And any nip of a dog to baby will be put to sleep no matter how old. Personally I just wouldn't create the situation in the first place.
For reference I have 9yr old lab and 1yr old baby. Dog is soft and playful around baby, acts on command if I need her to move, leave, sit, wait etc doesn't mind being pulled and pinched, gently, by baby and has adjusted to the baby being in the house, baby noise, new routines for walks with pram etc. But every day I do my upmost to make sure the environment remains safe for both of them to play together. Most of that is done by having such a well trained and well behaved dog.
I'm not paranoid, but accidents happen.
For the first time today baby put the ball in dogs mouth, took it back, and they played pass the balk for a while. It was lovely.