I have a small bump tha is sensitive to the touch on my upper left side of my lip. I've had the bump for a few days and the left side of my life became swollen last night into today. I researched canker sores and cold sores and it does seem of be either of them. I don't have any visible blisters or sores. Just a small bump on my upper lip a little below my left nostril and the swelling of the left side of my upper lip. what you tell me what this is and how to treat it?