I have had headache-less migraines in both of my previous pregnancies. I had several episodes with my first - the first time my left side was numb and I lost my peripheral vision, the second I couldn't see in the center of my vision, numb on left side again and couldn't finish sentences. Dr didn't seem overly worried.
Happened again with second pregnancy, lost all my vision except a tiny spot in the middle and again numb on the left side.

I did have GD with my first pregnancy, but not sure if it was related to BSL or not.

It is very scary when it first happens though - I was sure I was having a stroke!