Congrats!! I am no expert, but I think you are right to reintroduce whole grains etc. Perhaps slowly so you don't have discomfort. Early pregnancy does not take very many extra calories, but I definitely would not want to be in Ketosis. On the other hand, I would still journal all your food. It will probably be easy to overeat having come off such a strict low-carb diet to pregnancy.
Congrats again, so happy for you!