Question

what do you mean by darkening of nipple skin in bio??​

Answer 1

Answer:

Menstruation

The hormones estrogen and progesterone may make your breasts become swollen or tender before and during your period, which comes on average every 21 to 35 days. Some women also notice that their nipples darken before their menstrual periods or during ovulation — when hormones are shifting.

Answer 2

if your nipples gets darkening then you come in the age of puberty hope it helps