That is low, wugz, mine is naturally in the low side, I average 100/70, but I've gotten as low as 85/53....
Do you know what your average is? But low blood pressure can make you dizzy. I would just phone your doc and letting him know...maybe up your calorie intake(sugar), go for quick walks. It should improve circulation. Pregnancy can mess with your blood pressure though, around midway you're blood volume increases almost 50%, and if it happens quickly, it can strain your system. I think that's what caused my random super puffy legs and feet, system overload. Your heart may just be adjusting to the extra blood...couldn't pump the extra blood fast enough, but it will probably correct itself. Keep an eye out and keep track.