Causes for tender breasts?!

Causes for tender breasts?

For the past 3-4 days my breasts have been extremely sore. The tenderness is located on the outer side of my breasts. While I don't feel lumps, I can definitely feel hardness and thickening of the fibrous tissue in that area. I normally have a little soreness premenstrually, but nothing this severe and my period is still 10 days away. I also experienced tenderness during my first pregnancy, but not until I was about 6 weeks along. If I am pregnant I can't be any further along than 2 weeks and I have no other symptoms. Anyone have any ideas on what could be causing this or of ways I can alleviate the pain?

2 weeks ago
It looks like I caused a lot of concern so I suppose I should add that I do perform monthy self breast exams and have not noticed any problems so I do not think it is something too severe.

A friend of mine had sore breasts from over consumption of caffeine. Try cutting down on sodas or coffee. But you should still see your doctor if possible.