Today I Suddenly Developed A Strange Tingling Sensation In My

Today I suddenly developed a strange tingling sensation in my mouth, it felt as if my gums were swelling, then I looked in the mirror and there is a red rash on the insides of my cheeks and on my bottom gums, mostly on the right side. I haven't eaten all afternoon and this morning I didn't eat anything unusual so I don't think it's an allergy.. could it be from not cleaning my retainers in a while? If it's an infection what should I do?