I'm confused whether the spot under my eyes is melasma or dark spots. How can I tell the difference?

I’ve developed several very faint brown spots on my cheekbones and under my eyes, but I absolutely cannot tell with my own eyes if they are melasma, lentigo, or nevus of Ota. I thought it was melasma and was planning to sign up for 10 toning sessions, but I was told that if it is lentigo, regular toning won't work and I would need a completely different laser treatment. I'm totally freaking out now. Is there any characteristic I can roughly identify with the naked eye before going for a consultation? This is my first time getting pigmentation treatment, so I'm scared of getting ripped off. I would be very grateful if those of you with experience could share some tips.