Recently I have noticed that my areola's have increased significantly in size. I have also noticed the veins in my breasts are more visible. I've occasionally been able to see the veins slightly, but now they are very pronounced, particularly around my areola, a place I'd never noticed them before. I would say this transformation has occurred in the last 2-3 weeks. I do not have any additional tenderness in my breasts aside from the usual discomfort I experience at certain points in my monthly cycle. I have no other symptoms and am not pregnant. Any research I've tried to do all come up with pregnancy related answers.

Does this sound like a cause for concern? Pregnancy aside, what can cause these changes?

Thank you
Gm

You need to see your gynocoloist right away. You could be having a problem that is causing a false pregnancy (you have the symptoms but no active cycle) or you actually are pregnant and its not being detect by simple tests like home pregnancy kits.

Either way get checked out. There are other related causes too.