I can throw in some personal experience on how mood and tension level can affect blood pressure readings.
Blood pressure has never been an issue for me. Period... when I've had doctor visits, physicals and whatnot, it's been fine. I had an especially good going over about 2 years back getting ready for an exchange program in Japan (university required a physical, chest X-ray, vaccinations and whatnot). No problem. But, I never had any reason to feel nervous about going to the doctor, because I didn't think or assume anything was wrong with me.
Fast forward to January. I'd had a few episodes of abdominal pain during the last half of 2003, kinda like food poisoning, not terribly worrisome except it recurs a few times and I want to know what's up. To make a long story short the diagnosis is gallstones. I see a gastrointerologist and he recommends gallgladder removal, but as basically an elective procedure. Bottom line was my life is not in danger or anything, but I may have to deal with painful episodes. I decide to at least take a crack at improving my diet and supplementation to improve my liver and gallbladder health (the gallbladder stores bile produced by the liver, and one of my symptoms is elevated liver enzyme levels, so keeping the liver happy is a priority).
So a few weeks ago I went in to get a voluntary set of blood tests, to see if I've succeeded in improving my liver function. Important considerations are:
A) The last few times I'd been in I was diagnosed with the stones, and while my sypmtoms had practically disappeared, for all I knew the blood tests could come back worse.
B) This was the validation or invalidation of my entire life for the previous 4 months. When the GI recommended surgery, I decided that I was smarter and had a stronger will than the rest of his patients, and I chose to improve my health to treat the causes rather than cut out the symptoms. If things were the same or worse, I'd be demoralized, and all my efforts would have been pointless.
So, needless to say I was VERY NERVOUS about the outcome when I went in there, practically crapping my pants I was so freaked, and I could feel the tension in my whole body and my heart pounding... so I get called in and the nurse does the height/weight/blood-pressure stuff and I get "Is your blood pressure usually 140/something?" And I say "No, but I'm freaked the hell out right now. I believe it's been normal in the past, what's the chart say?" And she took a look at my past readings and they had been in the 120's/somethings, forget the second reading but they were nothing to be alarmed about. On looking at the old charts and noting my currently elevated heart rate, she didn't seem concerned, and said it was pretty common for people to get bunk readings when they are agitated. She said some patients can never get an accurate reading at the doctor's office because they just can't calm down. Had a cute name for the "condition" but I don't remember it.
As it turns out my liver enzyme levels had gone from highly elevated to almost normal, so I find it that much more unlikely that such an improvement in health would be accompanied by a BP increase... Maybe next time I will be able to sit still and get a good reading.
So, the point is, mood and arousal level will influence the readings... and you may be in trouble now that you're worried about your BP, it may be impossible for you to calm down when it's taken. You may need to get a cuff and just take it over and over again to desensitize yourself to the procedure.
Another thing is, read the fine print on the auto-BP machines, and they usually say something like they are not for arms greater than 13-inches in circumference, so they are not exactly T-man friendly. I have no idea how much of a factor that really is, but you have to figure if it's hard to get your arm in the thing before it's inflated (it is for me), then it's probably not going to work for you.
So, don't assume you're fine, but don't get too freaked out yet, especially when you have a good track record. Consider your mental state when you had the nurse check it- you'd already had two (probably bunk) high readings from the machines, so you were tense and worried about (expecting?) a high reading, right? And when you say no stimulants or thermogenics, do you really mean NONE? No coffee that morning? Tea? A large soda at lunch before you went? (OK, unlikely for a T-Mag reader, but you get the point).