Hana
Diabetes in pregnancy is a different ball game!
In fact and I know this by experience, in pregnancy you can go into DKA at a lot lower blood glucose level, in my case if my blood glucose hit 8mmol/l I started to DKA and was admitted into hospital, put on a sliding scale until ketone's were cleared, and then I wasn't allowed home until I had passed 48 hours without any trace of ketone's showing...
That is why the midwife is concerned that due to a lack of carbs, starvations ketone's are present, and they can't be 100% sure whether or not they are starvation ketone's or DKA brewing! So the OP needs to up her Carbs to more normal levels to rule this out..
Bexycat
Not sure what amount of carbs you were having, but up it a bit more but what I would do, is have a small regular amount of carb intake and play around, not sure what Bread you use, but if it's white try an wholegrain bread often this helps with spikes, another bread worth trying, tad expensive is Burgen bread, which is soya based if I remember rightly a lot of people find this solves a lot of spiking problems..
Diabetes during pregnancy is pretty difficult what ever type of diabetic you are, as your blood glucose responds different in each trimester, and can change at a drop of a hat.. The latter being more problematic for the T1 due to injecting insulin, as it can get very difficult to match dose and/or timing to maintain levels and avoid hypo's..
So I'm afraid it's a case of using your meter, testing and finding out what works best when in the day, as it may be that in the morning you can't eat many carbs at all, but later on in the day you can...