What does it mean when you have really noticable blue vains in your breast? I heard it was a sign of pregnacy is that true?

Varicose veins. Varicose veins can show up almost anywhere and will definitely become more noticeable during late pregnancy, but are not really a sign of pregnancy.
Maybe - nonspecific. This is a sign of breast engorgement; pregnancy can certainly cause it, but other conditions must be considered. Endocrine disorders such as hypothyroidism, hyperprolactinemia, drugs causing galactorrhea and even breast cancer can present similarly. See you gynecologist asap.