It looks as though you are experiencing some hormonal
imbalance. If you are above 40, you may have entered the perimenopausal age, thereby predisposing you to various subtle changes. Since your pregnancy
test is negative, you may wait for the next cycle, or you may see your doctor for a checkup. Breast tenderness is due to water logging that is caused by prostaglandins
. Please take further advice from your doctor. Good luck.