High Blood Pressure

Anyone else having difficulty keeping blood pressure maintained? They keep changing my dose, and some days it's totally normal (128/72) and others it's pretty high (142/102). I haven't been sent to hospital but I do have an ultrasound scheduled for next week at 35w to check growth of baby girl. Is anyone else experiencing this? What have you been told? I know stressing will only raise my BP even more, but I'm starting to freak out a little because I have heard all the horror stories of preeclampsia/eclampsia. Any input is greatly appreciated.