New mole, worried about melanoma

About 10 months ago I noticed a pale flat patch on the side of my face. Didn’t think too much of it. Then 3 weeks I noticed it had turned into a very light brown mole. I went to the doctors to get it checked. It was roughly 3mm and doctor said it was just a normal mole that had developed. Yesterday, I noticed it has darkened to a more dark brown. It must have changed colour rapidly as I didn’t notice it had changed until yesterday! I’ve got another doctors appointment again in 2 days to get it checked again. Is it likely to be melanoma? I’m 34.