What will the dentist do after swelling reappears after wisdom extraction?

So about a month ago I got my teeth pulled out (wisdom teeth), everything went according to plan. 2 weeks I was out of it and then the swelling stopped. So then I thought everything was going fine and I did what the dentist told me to do (flush out food in the gaps) and I did. But after awhile the wounds started healing and there was nothing to really flush out, so I stopped. Well about two days ago I felt a soreness in my bottom left jaw. I ignored it thinking I slept on my face a weird way. But it's been like this for two days now. And now I can see it swelling even. I already arranged for a dentist appt tomorrow but I want to know... what will the dentist do? Im terrified of another operation....