Hello and thanks for posting,

I think that you should be reassured by your GP. Veins can be prominent at different times, due to body weight changes, hormone levels during the monthly cycle, or skin temperature changes, or physical activity. So try to not over worry about this.

There is also some useful information about breast pain on this link,

breastcancernow.org/.../breast-pain

I hope that this is helpful,

Best wishes,

Vanda