Low blood pressure?

[Green Decals]

Does anyone have experience with low blood pressure during pregnancy? My usual, non-pregnant BP runs between 105-115 systolic. This pregnancy it has stayed there, but as I enter my final weeks it keeps getting lower and lower, to the point where I feel dizzy even when sitting or lying down. I am 38 weeks now and it is running between 90/54 and 96/64. I have been keeping up with my fluids because I know that I need all the extra blood I can to keep my pressure up, but even that doesn't seem to be helping. I also haven't gained much weight with this pregnancy, only 7 pounds. I do have hypothyroidism, which I am treating with armour thyroid and an herbal thyroid support.

Any ever experience this?