about a week after my surgery I began having a discharge from the incision used to gain access to my iliac crest....not blood mind you, just some gunk.....I received a 2 week supply of antibiotics and went on my way....but what a pain...I had to change my dressing 2-3 times a day for about a week....
With you having blood being discharged, I would certainly contact your doctor....one thing you are not supposed to do after they send you home from the hospital is bleed....