Some thoughts:

You should certainly eat enought carbs during pregnancy to avoid ketosis. Healthy carbs of course, such as fruit and veggies and whole grains.

You don't really want to lose weight during pregnancy because any catabolic state, even without ketosis, can possible effect the baby, especially in the first trimester which is so critical. It's probably fine to try to maintain your weight as much as possible.

My OB recommended cutting carbs (only by 10% though) as a way to decrease the risk of gestational diabetes.

The realities of being pregnant may throw all your plans out the window. For example - many women in the 1st trimester can only battle nausea by eating carbs, specifically things like crackers, pretzels and toast. Again, there's no reason why these things can't be whole grains.

Cravings. In my 1st pregnancy I craved french fries, and in my 2nd I craved chocolate chip cookies. I don't think these are the same as carb addiction cravings, but I don't pretend to know where they come from.

You can't help but gain weight in the 3rd trimester. The baby is growing so rapidly, you're getting swollen feet and legs (and face and hands . . .), your blood volume increases by 50%, the placenta is growing and amniotic fluid is increasing, etc. The good news is that most or all of this weight will disappear during delivery and the first few weeks after.

Anyway, pregancy is only 9 months of your life. If you can keep your weight gain between 20 - 25 # overall (most of it in the 3rd trimester), you will be back at your prepregnancy weight in just a few weeks post partum (although your shape will certainly not be the same that quickly). Think of it as a 10 month stall. I've had 2 babies and they're well worth it!