Big dogs and babies...

I have a very big dog and pregnant with my first baby. I am getting slack from every direction that I should get rid of my dog in case something happens. He's a gentle giant but does get wound up from time to time. He's 200 pounds and could definitely cause some harm accidently. I have another smaller dog yet no one says a word about her. I mean any dog could cause harm to a baby and my boy would never intentionally hurt anyone. I can't even think of re - homing him because he "might" do something. I am sure I am not the only person in the world thinking of bringing a baby into a home with a large dog...I have heard people say they instinctively know babies are sensitive and act completely different around them...anyone else in my boat??