Context: w/baby #1 I delivered with PE and HELLP at 25.6 weeks; with baby #2 I am now 36.3, although I've had quite a few scares this time around... My experience has been that stress has a HUGE effect, and the more I freak out about it, the more it stays elevated. Two examples: when my mother and mother-in-law were visiting and being annoying over Thanksgiving (right about 24 weeks!), my BP started going up, and as soon as I started worrying about it ("Oh God, this is it, here we go again"), it went up further—but as soon as they left, it went right back down. (I almost couldn't believe it, but I swear it happened. This was a difference of like 100/60 up to 130/85.) Likewise, last week, I was in the hospital for my weekly NST, and everything seemed fine: BP running about 115/75. Then they noticed I was having contractions (BAD, since I have a classical incision from last time), and by the time they got me down to L&D triage in a wheelchair 20 minutes later, it was up to 135/95. As soon as they figured things out and I calmed down, it was right back down again.
So it really could just be the stress! My advice would be: find something to distract yourself; stop taking your BP every five minutes (I've been there, I know the temptation, but I'm convinced it makes things worse); and check it again tomorrow. If it's still high then, call the doctor. You're not in diagnostic range yet, and even once you are, they'll want consistently high BP readings taken several hours apart (often 12!) before they'll decide it's PE. So rely on that: you have time to figure out whether this is PE or a false alarm. Meanwhile, breathe! Sorry about your worries! I hope this helps.
Pre-eclampsia and Stage IV HELLP, c-section at 25.6 weeks. RIP Felix (July 25-Sep 27 2011).
Expecting #2 in early March 2013. So far, so good!