I sorry to hear this.My son did this twice in the same spot and it tokok literally 3-4 months for the bump to completely go away. Do you have any arnica salve. I massaged arnica on it everyday and even without the arnica I massaged the spot. Good luck!
Yes the "eggs" are the worst. My DS had that too when he fell and bonked his head. Took a while to go down. I second the arnica.