Have you seen your doctor yet? Have you had any blood work - specifically thyroid - done?
If so, please post results (FT3, FT4, TSH, antibody testing, etc), along with the lab's reference ranges, since these are lab specific.
Could be a lympnode, especially if it is sore....
Not in the thyroid area? Thyroid is closer toward the base of your neck. I suggest getting an ultrasound of the area. :) Tamra