In general you want that headband on 24/7 for the first week, then at night for 2 to 4 weeks. don't be overly concerned with slight asymmetry at this time. Particularly if you had your surgery less than 10 days ago. As swelling goes down and scar tissue becomes more mature the position of the ears will change slightly. Keep close contact with your surgeon and have them monitor you.
If you do have some asymmetry that could be due to swelling or even a small collection of blood you definitely want to wear the headband.
Chase Lay, MD
double board certified facial plastic surgeon
Web reference: http://chaselaymd.com/Otoplasty__Ear_Pinning_.html