Is it a cancore sore or wisdom teeth?

I'm 21 and the left side of my mouth hurts really bad back behind all my teeth...the gum from what I see is a bit red and sensitive when I brush and feels different then normal when I touch it with my tongue. It's only been a day, but the pain is killing me. I have swished with both warm salt water and the mixture of hydrogen peroxide and water along with taking motrin to help with the pain. Is this most likely just a bad cancore sore from food that could have got stuck in my gum or is it a wisdom tooth coming in?