What Causes Bump On Inside Of Lower Lip?

Hi I`m 18 years old and in april, I noticed a bump on the inside of my lower lip it hasnt really changed it size, and there is no signs of leukoplakia, and is painless. It has been there for about a month. I started chewing tobacco 6 months ago but stopped in late march, I do not know what this is could someone help me out?