This morning while brushing my teeth, I hit my upper right gum with the top part of my plastic toothbrush. It turned out to be a small whitish cluster. It's lightly painful to touch and upon touching the area with my tongue I can feel a very small bump exactly where I got hit. Additionally, my upper and lower gums are kind of greyish black (this was from previous and not related to this incident). Can somebody please help me understand if this is something serious, can this be cancerous and/or what's the right way to proceed now? P.S - Whoever replies, thank you doctor for taking the time out to respond to my question and helping me out of this issue.