I am 28 years old and for the past month, my breasts have felt heavy and sometimes tingly, very similar to when I nursed. However, I am not nursing or pregnant. A couple days ago I noticed a dark, horizontal line between my nipple and bottom of my breast. It looks like an indentation, but it doesn't feel like an indentation. My OB/GYN looked at it yesterday and said it didn't look/feel like anything to be concerned about, but I'm still worried as this has never happened before. I have not switched birth controls, skincare routine, or diet recently. Anyone have similar symptoms or suggestions?