Is it a normal mole or melanoma?

It is recommended to see your doctor if you notice any changes to a mole in terms of size, shape, colour or texture. Darker patches of skin are usually caused by over exposure to the sun, so use a sun protection cream or cover up with clothing to prevent more sun damage. You skin patch is quite small so I doubt it is anything serious, but if it gets bigger then I would suggest seeking advice from your doctor.