I had people say stupid things like that too, people can be so dumb. I went for honesty option when my daughter Emily was born sleeping and insisted on people acknowledging my daughter but it took a lot of energy, ignoring tw*ts might be easier.
Your child has died for f**k's sake. I'm afraid there are a lot of dicks in the world. We all know here how much you love + miss your gorgeous son and he will always be your son and you are now and forever a Mummy so try not to get too devasted by the f**kwits and be kind to yourself it's such early days for you both
take care
xx