I'm a bit confused by your post. If you are taking Advair, I'd assume it is because you have some sort of breathing problems. Typically it is prescribed for asthma or COPD.
The best route to take to get your asthma officially diagnosed is to see a Pulmonologist. They will typically begin by taking a thorough history and doing some Pulmonary Function Testing. Often PCP's will diagnose asthma, but it is usually based on hearing wheezing when they listen to your lungs. Wheezing, coughing and chest tightness when breathing are some of the most common symptoms of asthma. There are some other types of symptoms as well that I have posted on the sticky at the top of the asthma board. Symptoms do not need to be "severe" for you to have troubles with asthma. One of your docs may give you a peak flow meter. While it does help you in determining your "normal" lung capacity, it isn't a good solo tool to diagnose your asthma with. It should be used in conjunction with the other things I listed above. The other test that is a "quick" test is a Spirometry done in your docs office. It gives a good snapshot, but the PFT's are much more thorough.
Asthma is a chronic and ongoing disease that affects the airways. There is no cure, but there are treatments to help keep it under control. Rescue inhalers are used to treat when you have flares or as a preventative prior to exposure to possible triggers. They are used as needed. Frequent use of rescue inhalers might indicate the need for daily meRAB to keep your asthma under control. Advair is one such medication. It is intended for daily use (typically twice per day actually) and is NOT intended for use as needed like the rescue inhalers are. It treats the two main causes of asthma symptoms which are inflammation and airway constriction. Daily use of Advair helps keep the symptoms under control should reduce the need/frequency of use of a rescue inhaler.
I'm confused as to why you would be taking Advair on an as-needed basis when it isn't designed for that purpose. In fact, it typically takes a few days before people really see results from its use. If you don't have asthma or only need assistance occassionally, it sounRAB like you should have a "rescue" inhaler which typically contains Albuterol.