Am I Getting the Right Dosage for My Asthma?

Question

My asthma is so much better and this time when I contracted a cold it did not for once become bronchitis which only goes to show that I am really improving. And the Pulmonary Function Test results were quite good. The doctor has told me that now he plans to get at my sinus and also try out a new medication to tackle my GERD as I have a reaction all the others medications or they do not work on me. Well what I was getting to tell you was that I have been given a sample of and also prescribed Advair 250/50 asking me to replace Serevent and Pulmicort with it. But Advair 250/50 is just one inhalation while I generally take 2 puffs of Serevent MDI and two puffs of Pulmicort on the Turbohaler two times daily. So on these two I am taking 400 twice a day and if I took only one puff of Advair 250 twice daily I will only be taking 500 instead of the 800 I was taking. Do you think my doctor has made a mistake, or id he beginning to go out of his mind or is it that I am getting confused??