I got stitches taken out about 3 weeks ago above me knee. I got dissolvable stitches inside. There is a white soft scabby spot at the end of my scar. And there is like a little piece of stingy stuff in the middle of scar. What is this and what Should I do?

Leave it alone. If it doesn't go away in a little bit go to the doctor to see what it is. If it is still there in a week go see a doctor. Keep the area clean and covered for now.