Do you feel that your breast are red? Blushing? If you are warm or flushed, it's possible your breast will flush just like your cheeks, and you can notice this without concern. If one sided blushing, then yes, you might consider that there is something to cask your gyno about. Of course we think first of hormonal changes. The most common hormonal changes are due to pregnancy. And remember, if you are checking the pee test, pregnancy tests are most accurate first thing in the morning.