Suggest Treatment For A Bump In The Mouth

Okay so.. I have a bump on the corner of my mouth, and it's actually been there for a few months. My mom said it's a cold sore, but do they usually stay for this long? Plus it doesn't hurt at all, not even when I touch it. It just feels like a bump. It's not really red..
Here's a couple pictures of it that might help
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So how do I get rid of this sucker? Is it even a cold sore? Is it normal that it's stayed for so long? And what is the best thing to use to get rid of this when it's not even an open cold sore?
Thanks