Push your doctor to get the results. Tests do not always come back positive even when you have the disease. Diagnosis is always difficult and experienced docs look at clinical symptoms and labs to make a diagnosis. Some cases are particularly difficult and inexperienced docs can struggle to make a diagnosis. Going to an ER would be counter productive unless you are truly in an emergency.
Early diagnosis and aggressive treatment is best but not always possible. Short course treatments usually do not work. Long term treatment of some type is more likely to be effective. Depending on the severity of your symptoms will determine what course to follow. Prednisone works fast and is usually effective but there are sometimes serious side effects to long term use so most docs will introduce a prednisone sparing suppression med for long term treatment. if your symptoms disappear over the course of many months or a few years then you would consider tapering off meds. One of the biggest mistakes newbies make is to have short course treatment, see their symptoms disappear and then go off all meds. Symptoms usually come back and you start over again.
Call your doctor to see if the rest of the test results are in and ask for a copy of the full report. I have copies of every test I ever had over the past 22 years.