Is it normal that I still have severe pain 12 days after Bone Graft surgery?

This is not normal to have severe pain almost two weeks later after a bone graft. If your dentist says it's healing well, I would seek another opinion from an oral surgeon or periodontist if possible. Certainly, if you choose to wait, if you are still in pain in a week or two, then I would definitely find another specialist to help you. 

It is normal to experience mild pain and discomfort over the surgical area for the first 2-4 days.  It is very unusual to be in pain two weeks after the procedure.  I would go back again and if the issue is not resolved seek out a second opinion.