Small boil like White on WT extraction.

I had extracted my upper right wisdom tooth one and a half month back. I had severe lower jaw pain under the ear lobe with swelling. So, I went to the dentist and x-rays was normal. Told me to extract upper right wisdom tooth for my lower jaw pain. I went to the OMFS and removed the upper wisdom tooth. No stitches. I went for follow-up after 2weeks. He said the site is healed and taken a xray to check. Now, I feel some small boil like lump on top of the extraction site. It's white and small pimple like boil. It's hard when I run over my tongue on it. It's on the gum area of the wisdom tooth. I still have the whole in the extraction site and it's not closed yet. Is it normal ? Do we get abscess on the extraction site? When the whole will close and gum form?