PRICK EARS

I have researched this on your GTG search, but am not finding my particular situation. My "Harley" 5.5 month old male has what I believe to be one (1) prick ear. Is that common to have just one and not both? He is teething so maybe this ear will return to normal? The "correct" ear is perfect, it is the other "incorrect" ear that droops slightly at the top, but 90% of the time stands straight up. I'm having him neutered next week and will also inform the breeder. I don't care, it makes him "My Harley", but just curious if one ear is common to prick ears.