Swelling, Possible infection after wisdom teeth extraction?!

I got all 4 of my wisdom teeth removed 9 days ago (Jan 13th) they were all impacted. I haven't had any real problems until today. Mostly all of the swelling has gone away and 2 days ago my mouth was almost back to normal. But yesterday the bottom right started hurting and is all red and swelled up and I can't close my jaw again. Could I have an infection or is it something else? There is no white around the area and it is rather annoying. Anything I could do to help it? My dentist isn't in over the weekend.