How long it requires for complete healing from septoplasty?on my 15th day after surgery,still get a drop of blood with post nasal drip sometimes.

Several weeks: Healing after surgery is a process that actually continues to some degree for a long period of time. Scar tissue continues to mature and remodel for several months. The bulk of the healing process, however, is done after about 6 weeks. At 2 weeks I would not consider a bit of bloody mucus here and there abnormal. If you have any concerns I am sure your ENT would be happy to take a look.

See your surgeon: Have your nose evaluated by your surgeon to determine the source of blood.