The fact is that unless you are Lutheran or Anglican or Prebyterian/Reformed, your group is not "Protestant" -- just as many insist that Seventh Day Adventists or Jehovah's Witnesses etc. are not Protestant. Because these groups and others split from the original 3 splits, these groups are not Protestants -- some may even argue that some like the Jehovah's Witnesses are not Christian -- other freepers may say the same about Oneness Pentecostals who deny the Trinity
I prefer simply to be known as a Christian because I follow the Lord Jesus Christ - my savior, redeemer and God - as well as His teachings to His disciples as written in the divinely inspired Holy Scriptures. Even "non-Roman Catholic Christian" helps to differentiate. What REALLY matters is that the Lord knows those that are His and His own hear HIS voice and follow Him.
But, as the saying goes, "Call me anything but late for supper.". ;o)