Veg is a good way to bulk out meals and is mainly very low in carbs, as well as being good for you and baby, of course
Is there any veg you like? Salad?
Breakfast coukd be berries and Greek yoghurt, or cheese in toast, or hard boiled egg and bread and butter
Lunch - sandwich with protein and maybe a glass of milk
Tea - curry with measured amount of rice according to your carb limit, or chilli with small rice portion, or salmon fillet and baked potato (weigh to check carbs) or Spaghetti Bolognese with small amount of pasta (weigh it again)
You may find your clinic has some meal suggestions. Have you seen a dietician?
How many weeks pregnant are you?