Been having a really bad few days with really bad chest pains and coughing along with wheezing had to take my blue inhaler so much as seretide is not doing me any favours. but i have found during the last couple of days peak flow has dropped down to 220 at worse but i keep getting mixed readings one moment at 300 next i am at 230 am i breathing differently every time i test it ??? i am not spiting or coughing into it so what is causing this ???