Are the white spots on the extraction sites the bone?

I finally had my wisdom teeth removed and I have no pain just a little soar but I'm a trooper. But a day ago I saw white spots on extraction sites is that the bone? I'm scared but at least I have no pain which is good as day by day I feel better. I would feel even better if I knew what the white spots were because they get me nervous as I heard of a dry socket of the bone popping out so.... a little scared...Plz help.... Is there a way to prevent a dry socket?