Congrats on the pregnancy...
I can't answer the question whether your dog will do well around a baby.
We have a Jack Russell which I am in the middle of training not to nip and I found this technique to be working....when she nips I poke her and say no (use your word). She seems to be catching on. Nips have definately decreased.
If this does not work for you two then maybe a trip to obedience school might be in order.
If you watch a mother dog with her pups she will nip at them to keep them in line...so my poke (not hard) works thus far. Ah...maybe that is what my JT is trying to do to me...keep me in line

However I'm the bigger dog in this house!