Congratulations on the pending arrival.
You should not try to be in ketosis NOR to lose weight while pregnant. But while you SHOULD gain the weight needed for a healthy baby, you could still eat a very healthy diet by cutting out the sugars, starches, baked goods, junk food and carby snacks.
Instead of white bread, buy the most "grainy" kind you can find. Or a low carb bread if it's available in your area. Whole grain cereals (the hot kind) are excellent in nutrients and wouldn't put on fat if you don't use sugar on them. Avoid all cold cereals that have sugars added or sugar flavourings.
Vegetables and salad are always good. You need fruits for the vitamins. And dairy for the calcium to make baby bones.
So forget about not gaining the weight during the pregnancy. After you have a healthy little darling to hug, you can work on losing the fat.
The Maintenance menus for any low carb plan will give you excellent ideas of how to eat: Protein Power, Atkins Maintenance, The Schwarzbein Principle. They all list the sort of foods to eat and many to avoid. But don't do the initial phase of any of them until Junior arrives. Eating this way will also help stabilize your blood sugar levels and perhaps the blood pressure too. But do listen to your doctor.
It's not the weight, it's the fat we want to lose.
All the best.