What Can Cause The BP To Come Down Low?

My blood pressure has been in the low normal range for most of my life. Today, I took part in an experiment and had my blood pressure taken twice-the second time two hours after the first. I was sitting in an air conditioned room, and the experiment wasn t stressful to me, nor did it require any physical activity. The first reading was 130/83 which surprised me as my pressure usually ranges between 115-120/70 or something similar. The second reading indicated my pressure was 160/84. The reading were taken on an omicron wrist device. What really bothers me is why it got so high in two hours. I do take adderall (30xr), but have always had good pressure readings when I go in for my refills. I recently started 100mg. of Wellbutrin which might be the culprit-at least I hope that s it. I m 62, in really good health and I walk or bike daily for at least 2 miles. My question is will it be safe for me to aqua jog in a pool or do other strenuous workouts while my pressure is this high? I can t get an appt. with my GP until next week and really want to know if I ll have a stroke or heart attack soon.