What Causes Pain And Scabbing In The Previously Injured Area?

About 3 years ago I fell on my knee and required 9 stitches. I'm 6'2'', weigh 235 lbs., and I'm 27 years old. I've been working out more lately (specifically cycling) and I've noticed some dull aching around the scar. Tonight I noticed some mild bleeding and scabbing. Is this something I need to have looked at right away? I was planning on going to my general physician in 3 days anyway. Can I wait that long?