Hole will close
What you are describing sounds like an expected healing: first, there will be blood-filled hole, then gums start growing over the hole.
Underneath the growing healing gums, the 'socket' --a hole in bone left after the tooth is gone--starts healing. The hole in the bone will be gradually filled with new bone cells. Isn't the body amazing? After extraction, it is a good idea to have a post-op check.