I had low BP at the beginning of both of my pregnancies. At around 5-8 weeks my tongue would go numb, I couldn't make a sentence that anyone could understand and I would feel disoriented and it was followed by a migraine. It wasn't ongoing, it was like a sudden drop in BP and then a few hours later it would return to normal. The doc said it was low BP. These 'spells' happened a few times but after about 9 weeks I didn't get them anymore. My last pregnancy ended with high BP (155/95) and I was induced, and I am now 25 weeks but have had normal BP through my second trimester.