I suffer from those migranes, but luckily haven't had any whilst pregnant

They are terrifying. Especially if you have no idea what it could be. I have had them since 12.

Usually the same side, tingling in the arm, face tongue, eye. really bizarre. I also get the visual disturbances and kind of like a black spot in my vision. It's awful to try to talk to someone when you can't see them properly and you slur your words and can't get out what you're trying to say.
then i usually get the calm before the storm for about 10 minutes then BAM biggest most awful thumping headache that you just cannot escape.
I'm sorry for you, and anyone who suffers. they are awful. I usually just have to ride it out till i stop throwing up, can get some painkillers and water down and try to sleep to escape the pain. a few days and i am ok. Although i have had a few bouts when one seemed to come just as another was finishing and had an awful lot for about 3 months straight. Of course lots of tests ect...But have noticed the pattern tends to get me after stress. Once it's over i seem to get struck.
I have been told to have asprin straight away at first symptom, but i know you can't take them pregnant. I'm not sure about your sugar levels, sorry, i have only had the migrane symptoms.

Hope you are feeling ok, take care and i hope you get some answers
x madame x