do i go to gp?

Hi all. 

Ive had this strip running down the length of my nail for around 2 years now that ive been concious of and have had in the back of my head as a sign of a subungal melanoma. however i've never gone to the gp as my mum insisted it would be nothing (i am u18). The cuticle has never healed. 

i would be very grateful if anyone knows anything about this and if i should urge my mum on.

thanks.