Nipples ?

Okay so the past couple of days Iv been trying to decide if my
Nipples have gotten darker. (My period Is one week late today) and if notcied they get a dark purply color when I'm in the shower, or standing up or sitting up. But when I'm laying down or cold there not as dark and the spider veins are only visible when I'm setting up or standing up or in the shower. Is this a sign of pregnancy even if there not that dark purply ALL the time? Bc I know when your standing and sitting more blood goes to them so if they purply then usual they must be getting more blood bc of the hormone correct? Or am I wrong? Thanks for any advice.