It's just a Bad Idea to fly until you are definitely clear. Even after it has stopped hurting there's still lots of rubbish in your ear. Until your body has it's own chance to clear this, side effects of flying can range from mildly uncomfortable to extremely painful. That's sort of ok on an airliner when you're not flying and you can dose to the gills on painkillers. It's not when you are PIC of a light aircraft.
I speak from some experience.