I had a tooth extraction due to severe pain in my tooth, the pain is gone but there's still a little swelling at the upper side of the tooth next to it?

Swelling: How long ago was the tooth extracted? Without personally examining you, we can't determine if what you see and feel is normal post-operative healing or something else. You will have go back to your dentist and have him\her take a look.

Reevaluation: Hard to tell without examination. If it has been more than a week since the extraction, swilling should have disappeared. In any case, return to your Dentist to evaluate the surgical site, the health of your gums/bone, the health of adjacent teeth, and to plan for replacing the extracted tooth to prevent bite collapse.