Where the two parts of my gum have been stitched together from wisdom tooth extraction has not formed correctly. should i be worried? 8day old extract

No: Will smooth out over time, perhaps as long as a year. If you are concerned ask your Oral Surgical Specialist to take a look.

Extraction: I assume you are talking about the tissue directly behind the second molar (12yr molar). I would not worry as it is still early in the healing process however i would ease my mind by seeing my surgeon to have them check the area.