Not usually no. And please don't be offended but I have to ask didn't you consider all the pitfalls, pros and cons beforehand? Research the breed? Find out if it was suitable for your way of life and so on? What it would take to bring a puppy along in time and effort?
Tbh if it were me I'd not have gotten a GSD puppy at 28 weeks PG. Well, your OH should not have. I'd have gone for a more manageable size of breed and also something probably more suited to your lifestyle and requirements.
Puppies are hard work, require toilet trainining, exercising and socialising as well as attending classes to train them properly (guard breeds especially its worthwhile). You cannot neglect any of this with that kind of breed of dog. Its bred for guarding etc so really needs a firm decent hand to bring him/her along. Shutting it outside if it gets too much or not walking it etc would be a recipe for disaster. You also need a calm environment for them as anything tense or so on they will pick up on and it can affect them and how they develop with people and react etc.
Also puppies and small children would be a concern. Not saying a pup or dog would harm your child when it arrives, but GSD are a very loyal type of breed and need careful considerate handling to introduce them to children. They need to know their place in the order of things and a baby can unsettle that as the attention you can give it now will probably be far less once you have your baby here. And also as you reach the latter stages of pregnancy you'll be able to do far less with the dog in terms of handling etc.
As lovely as many GSD are I don't think they are suitable dogs for first time dog owners especially when there is going to be a young child around. Even if your OH has owned one before, you have not. Who is going to be the one to care for it mostly if your OH is out at work? Or is he home to put all the time and effort into it and to continue with it after your child is here.
Another thing with GSD is the hip problem. Its inherant in the breed and it will need to be hip scored when its a bit older. If its not got a decent score you can expect problems aplenty and possible large vets bills for treatment. Hopefully you bought from a reputable breeder who had hip score results for both parents that were within acceptable margins as it at least offers a decent hope that pups will fair ok also.
We recently lost both our dogs and after careful thought decided to get a new one before our baby arrives. However, we felt that a puppy would have been too much to take on now and keep up with once the baby was here so opted to go for a 6 month old Whippet. Whippets are lovely natured, sweet and not aggressive with people. Yes they may chase rabbits, but with people they are lovely. They are also a manageable size for me being pregnant and also when the new baby arrives. I won't be having to deal with pushing a buggy and training a dog to walk to heal and not pull me along with it. We considered other breeds also, and I've owned many dogs in my life from Dobermanns to Gordon Setters, Dachsunds to cross breeds and I like to think I know my breeds and what suits us. So we decided on a Whippet and have to say its been lovely so far. We looked at all the options and our lifestyle and what we felt we could cope with for the next 10 plus years.
There are many great breeds of dog out there far more suitable to be around a young family and that will require far less handling and training and are much more suited to a family life. Getting the wrong dog now will probably mean it'll be in a rehoming centre sometime in the future through no fault of its own. So many people get the wrong kind of dog for their lifestyle and personality its not funny. I find it heartbreaking to see so many GSD, Staffies, Rotties etc in rehoming centres. People get them not realising just what effort they require and when they cannot cope with them pack them off for rehoming.
I'm sorry if this seems like a rant, its not meant to be, just my honest opinion as a dog owner myself. I've seen too many dogs fall by the wayside because people simply didn't realise what they were taking on and it breaks my heart. I really do wish you all the best with your dog but think you should seriously consider everything if you've not already and if you have doubts then return the dog to the breeder asap and go find a breed more suitable for you as a family.
Good luck
*ETA* And yes, I do have experience of GSD. My mother has kept them for many years now and I am used to being around them, handling them and having them in my own home and visiting her house also.