Small spot on gum on top of gum where wisdom tooth uses to be, looks blackish red. No pain, no swelling or bleeding, and wasn't there yesterday. I don't smoke or drink. I'm 23 and have no sliver fillings.?

Bruise. It is not uncommon after an extraction to have the tissue more vulnerable to minor trauma. Any chewing in the area could possibly traumatize it. So unless food was forced under the gum the area should heal well. Leave it alone but if it lasts start warm salt water rinses in the area.