In just the past week, my gums behind my last tooth on the bottom right have become a bit inflamed and sore. i haven't had my wisdom teeth removed. ?

Wisdom teeth: Sometimes wisdom teeth are valuable asset when healthy and properly aligned, but more often, they are misaligned and require removal. The removal of wisdom teeth is one of the most common procedures at ages 15-24. See your dentist for evaluation and x-rays.

See dentist: Call your dentist and get an appointment. Ask what to do till then for this. Also, ask what signs to watch for that would mean you had to call back or get seen before the appointment date. Brush, floss, and use mouthwash recommended by your dentist at least twice a day 3 times would be better for now.) You could gargle/rinse with warm salt water (1 tsp in 1 cup of water 3-4 times a day too.)

Pericoronitis: ..is the term for this. Sometimes it's caused by the upper third molar irritating the tissue behind the lower second molar. If that's the case, the solution may involve removing the upper tooth to relieve pain on your lower jaw. In any case, you will need to see a dentist for a clinical and likely radiological exam to develop a treatment plan.

Gum or tooth: Could be gum issue, such as pericoronitis (gum inflammation around crown of an erupting tooth) or a problem with an erupting or impacted wisdom tooth. Call your Dentist. It may be time for you to see an Oral Surgeon. Even if it starts to feel better you should be examined.