If you are worried about ketosis, then dont be. I think a tablespoon of curry powder has about 6g of carb in it, and i doubt you are using that much.
The official line (from a medical site i saw once, but cant remember where) states than anything less than 130g carb a day is low carb. That sounds pretty high to me, for instance 1 slice from a small hovis is 9.5g of carb, so on the basis of the official line you could eat almost a loaf and half a day and still be low carbing.
I think the generally accepted level is 80g or less a day, Exante gives you something like 58g a day, so a few extra carbs and minimal calories are not going to hurt, especially if it makes the soups more palatable.