Molar extracted and bone graft placed. 2 weeks later, the area still hurts. What could it be?

My right molar had to be extracted because it got infected. 15 years ago I had one root canal done to it. Then 10 years ago, I retreated it because it got infected again. So, recently, the same molar got infected for a 3rd time. So, my dentist told me to get rid of it and put in an implant. When he extracted it, the molar broke into pieces, but he got it cleaned out and put in bone graft from a cadaver. 2 weeks later, the pain subsided, but i still feel pain. x-rays look nice. But y the pain?