Sorry for so many posts, but now I'm worried the reason my peak flow never lowers is because I've been recording it wrong. Or at least I think I have? The only way I can describe my mistake is that I breath out using my "throat" instead of letting my chest sink in. Sorry if that sounds vague, but is it enough to say I've been exhaling wrong when taking measurements. When I tried exhaling more from my chest, my peak flow dropped by almost 200 points! Usually it's 700 - 600, even when I feel bad, but now I feel like it should be lower, especially during symptoms.
I can only hope I'm being paranoid.