I have very minor throbbing ear pain for 2 days. it sort of comes and goes. what could it be?

Could be an ear infection. Have your physician take a look if it persists

If swimming or a lot of water exposure lately you could have an external ear infection (in canal) but if you have cold/sinus symptoms it could be a middle ear infection, or if you have a sore throat that can refer pain to the ears. You could try 2-3 drops of hydrogen peroxide in the painful ear twice a day for a couple of days (might help an external infection) & Tylenol & see Dr for exam