I have low BP normally and it goes even lower during pregnancy too. There are no medications or anything you can take, and it doesnt hurt your baby but it can hurt you if you faint!

One thing that my dr and my gym instructor both said was I could increase my salt intake (a slong as your cholestoral is up to it ). I did this by adding salt to cooking which I didnt normally do, not a lot but enough that it made a difference. I also made sure my heart rate didnt go above 140BP when exercising or I would get dizzy and faint. And if I was feelign dizzy I would sit down and put my legs above waist height (ie. on another chair propped up) and have some sweet orange juice, that usually worked.

Hoep you feel better
xxxCaz