Is Normal To Have Darkening Of Vaginal Lips With Onset Of Puberty?

Hello! I'm only 16 and still a virgin and I have notice that since I've started my period at 14 that my inner lips have began to darken. Is it normal or is there a way to get riid of it? I'm really embarassed about it and don't wanna ask my mom or a doctor, so can you help me? Is there a medicine or cream to lighten it up?