any ideas on a black and blue?

hey guys i am one of those who injects slowly and does not dart last wed i did an injection in the quad it went in slowly no pain blah blah blah when i pulled out blood squirted up in the air and then i covered it with a cotton ball, next day on the location spot i got a little lump with a black and blue it is monday and it is still there but it does not hurt when i touch it and it seems to be going away, but any intel would be helpful on what the problem is or was.AJ

You have a Sub Q hematoma. In short it is a collection of blood under the skin. It will fade and go away.