A couple of days ago I noticed that the gum right behind my very back tooth was a little swollen and sensitive (this has happened in the past and would go away after a couple days).  It has gradually gotten worse, but seems to get worse when i bump it with a tooth brush or bite down on it.  It is almost like a compartmentalized knot with very little swelling in the surrounding area.  My question is what should i do if it gets much worse considering that this is friday and I don't see myself getting to a dentist until monday at the earliest.  Thanks for any help.

drink alot of alcohol

i got nothin

pre-eruptive wisdom tooth?

I only guess because I have one that is erupted but lays horizontal and gives me problems for a few days 2-3 times a year.

Ibuprofin takes care of it for the most part for me.

Gargle with warm/hot salty water.

If it is that bad, and you have a good relationship with your dentist, I would call now and tell them what is going on. 9 times out of 10 my dentist  will tell me to come in ASAP so they can take a quick look, instead of dealing with an emergency weekend call, and if you do have a nasty infection, sooner or later you are going to have to head in and deal with it. BTW, I'm not a dentist, but a bunch of my cousins are.