I am losing hair in the center of my head. i got surgery there a three months ago there and it still hasn't healed yet. not a major surgery?

Scar tissue: If you had some skin removed from your scalp in this area, the resulting scar will often not support hair growth. You indicate that it is not yet healed, which leads me to believe that the wound closure was tight, further complicating the problem. The blood supply to the scalp is excellent, so this will heal. The hair from the surrounding areas will usually cover any bare areas.

Circulation: Your recent surgery could affect blood supply to the hair follicles , which should recover with time. Difficult to discuss without knowing reason and type of surgery.