" moustache" that isn't really there

[Primadonnagirl]

Please help me cos I'm developing a real thing about this. I have very fair "English Rose " skin I.e pale, prone to blushing and v sensitive. BUt I have quite dark hair although not v hairy. I usually get my eyebrows threaded once a month and upper lip every two.But recently the beautician has been saying there's nothing much to take off my upper lip..yet I can definitely see a darker line at the mouth

I can see it even though I use a light foundation and it's more noticeable when it's pm and my make up has worn off.I can see it in harsh light like ladies toilets etc. The thing is I have a job where I'm often doing presentations etc so hate to feel self conscious but equally cos of sensitive skin don't want to get threaded unnecessarily cos I always get red spots next day anyway.
Does anyone have experience of this..if there's no hair there what's causing this moustache?? I'm in early menopause if that makes any difference

[HollaAtMeBaby]

Could it be hyperpigmentation?