9 days post op FUE, how can I know the different between graft falling or it's just hair? (photos)

The photos look like grafts.  Some look like transected grafts. It is NOT very clear.  It may be scabs. YOU CANNOT DETERMINE THESE THINGS WITH PHOTOS.   If you are concerned you may want to follow up with your doctor.

This is a normal process that happens to many patients at that time. Transplanted hair falls off about 2 weeks-1 month after surgery. Scabs may come out with hair but you should not worry about this, in most cases hair grows back normally.

What you are describing is a fairly normal process. It can be challenging to evaluate all the bizarre shapes of hairs that are lost and shed post transplant. Most of the time after 5 days hairs that are lost are hairs that are ready to come out. The genetic information to grow a new hair is left in the skin. Keep up with the post op care your surgeon outlined to you. This is the best way to ensure you don't lose grafts. 

Many patients are concerned after a hair restoration procedure that the grafts will become dislodged and fall out.  Shedding of the small hairs attached to the grafts is normal.  These usually appear as tiny hairs and can be covered with some crusts.  When a graft becomes dislodged,  there is usually associated bleeding.  If you are just seeing small hairs without any bleeding, there is no concern.  The debris in your photos appears to be part of the normal process.

In every patient, the graft shed (fall out) and then in 4-7 months they regrow. The shedding that happens spans 2-6 weeks usually, but they can happen even after that.  This is normal, so don't worry.