Well it's been an hour since I got back from running and it's still only improved to 450, which is still below the recommended value for my age and lots below my usual peak flow.
My doctor just told me to do what I'd normally do and measure my peak flow lots so he can asses it when I go back. When I approached him yesterday it was with the intention that I get wheezy following bouts of exercise (even really short bursts like 10mins running), so I thought it was sensible to try and do some exercise and then measure it so we can get a good assesment of it. But now that I've done it and seen it drop by 100 has made me worried incase I am actually worse than I realise - yeah I feel really wheezy, tight chest, slightly light-headed when I get back from exercise, but it's been like this for years that I've always assumed I'm just really unfit (even when I was in training for my college rowing team, I just assumed I was more unfit than everyone else). But it was when I went to Paris with my boyfriend and we climbed the steps up the Eiffel Tower and I just felt completely unable to exhale properly that I realised it might be a good idea to see someone. I also keep waking up feeling all yucky on my chest, which I never use to (I know it's pollen season, and I developed hayfever last year, but I'm taking medication for that and I'm not getting any symptoms, so I presume the reason I wake up coughing up phlegm isn't due to the hayfever).
Maybe I'll just try going running a couple more times before I see him so I can show him that after exercise it really does dip and then he'll have a better idea of what problems I'm experiencing.