What Causes Dark Round Mole In Stomach Region?

ive had a dark round mole on my stomach region since i can remember, and i also have another mole aproximately 5-6mm in diamter on my right thigh, ive had this mole for few years now and no changed have been seen.. but i am still concerned, i have checked cancer cymptoms which as far as i know i dont think i hev except the stomach mole is black and has sum area which is just skin or faded black...i am 20 year old male and am very concerned..please can anyone tell me if i am ok?