Welcome to the forum.
Is the right side of your face swollen?
Any other symptoms perhaps, like pain or tingling?
A tooth abscess or other dental issue may cause it. (Dentist)
If not, check for common food allergies. They can affect either side.
I used to react to eggplant in the past, and it always affected my right side.
Keep an eye out for peanuts and other nuts, shellfish, wheat,eggs,dairy,soy, as they are more common than other foods.
I can't think of anything else unless there's some kind of a tissue infection
on that side of the face. (Dermatologist or Infectious disease specialist)
My suggestion is to see your PCP first, if this persists.
Hope this helps.