I have 2 Labradors, you would never have guessed 
We got our youngest lab as a puppy when DS was about 16 months old (DS is 7 now) and DD was 3 (she's now 9). She's amazing with the children, incredibly protective of them.
We got our older lab as a rescue dog about 4 & half years ago when she was about 5. She'd been given to the home as she was pregnant and had obviously had many litters already. Her 9 pups found homes straight away and we just fell in love with her. She had really bad mastitis at first and a very saggy tum. The tum still sags but is so much better these days.
Anyway (I could go on about my lovely dogs all day), I don't think either of them have been different with me, I'm 9 weeks pregnant.
I like the idea of a cd with baby noises, that might be a good idea. I think we plan to take it very slowly when baby comes.
My younger lab had a crate for the first 18 months which was her hideaway from the kids when she needed it. We've since had an extension and the utility room is now the dogs' room, so they will have their escape in there.
Our dogs don't go upstairs either but we are having to re-jig the house and planning on moving our bedroom to a downstairs room, which baby will share with us for 6 months+
I do love my dogs and I think you can easily have dogs and a baby with forward planning and being responsible. I still keep the children out of the kitchen when the dogs are eating. They haven't snapped but I don't dare take chances, they're still dogs at the end of the day, as much as I snuggle them and call them my babies 
I think it will be harder to exercise them when baby comes but I think with planning it will all come together. I don't think I'd feel comfortable walking them with a pram (they're quite big dogs) but I hope it will be my 'me' time, walking them, as it is now.
Sorry for such a long post, I didn't plan on going on so much.