Picture Of Cancerous Moles Could This Mole Be Cancerous?

Could this mole be cancerous? - picture of cancerous moles

Sorry, no pictures, but I started to worry when I noticed a mole on the left side of his neck ... Today I am light skinned and had the mole all my life and I am 18 years ... rise and from what I see, symmetric ... the center is dark brown, while the outside is easier, and it is clear that the center is much darker ... is slightly smaller than an eraser .. I will dermatoligist in about 2 weeks, I have nothing to worry about the meantime? I can not help but think about what could be a sign of a melanoma? Medical advice is appreciated