3 months post op FUE. While washing my head a scab fell out with a hair with a black bulb. Is this a hair graft? (photo)

After three months there is no way to lose a graft.  If you see something out of the ordinary it may be best to contact your doctor.  Otherwise you may be seeing an old scab.

Transplanted graft’s hair starts to shedding in the first week of surgery and may go on untill 4-6 th weeks after surgery. İt is not surprising to lost approx.  %70-80 of all transplanted hair shafts in first month when you are washing, gently rubbing  or touching the head. İt is shock loss and not permanent. I think that  hair with bulb is a remnant of improper cleaning of head. 

Most people shed the grafts starting on the first few days. They may notice whitish crusts that look like grafts after washing and may even see these on the scalp after washing. These whitish bumps are grafts that have taken on a bit of water in the skin of the grafts, just like your finger get water-logged after you swim for a while. These crusts/grafts will shed over the next 3-4 weeks. IF have significant crusting, you did not do the correct wash immediately after the surgery as you should not have any significant crusts by the first 3-4 days. 

At 3 months post-op I would not be concerned about you losing any grafts. If you do have any concerns it is best to mention them at your follow ups with your doctor to get an assessment.