Ok a lot of people are saying that if you have the 'blue veins' then thats a pretty good sign that you are preggers. But I have those blue veins that are very dark and the tip of my nipple is very purple. My boobs were never like this, I went to the doctor (i thought I was pregnant) and they told me that I wasnt and that I had an infection. Does infections cause that? What other things cause this? Anyone know?