Pea-sized bump under chin, trouble swallowing, sores in back of mouth near wisdom teeth. is it cancer? any other ideas of what it could be?

Canker sores: A canker sore is a painful sore in the mouth. They are usually white or yellow and surrounded by a bright red area. They are not cancerous. This may be what you have. The "bump" under the chin is likely a reactive lymph node- you body's way of reacting to that sore. You can try different home remedies and mouthwash and they should resolve within 1-2 weeks. Otherwise go see an ENT or oral surg.

Probably not cancer: I would also suggest seeing an oral surgeon or ENT if it gets worse or is not gone in a couple of weeks.