What are the veins and purple around and on my nipple? (Photos)

any advice will be a great help!! i first noticed the veins a few days ago. they don’t hurt to touch but i have never noticed them before. i overthink a lot so i’ve been googling and it keeps coming up with cancer??? the veins aren’t on the other nipple just this one. my period isn’t for another week but some sources have been saying that it normally happens before you’re due your period but i don’t know what to do please help!!