7dpo and darkening skin

Hi everyone,

I have noticed that the skin above my upper lip has become really dark all of a sudden. My friend is sure I am pregnant. I popped on here and saw Im around 7dpo. Has anybody else experienced this? I think its too early to take a test, but I really want to try to lighten the skin asap but wouldn’t want to use anything that could harm a baby. Has this been a symptom for anybody?