Reason for breast enlargement besides pregnancy?

[WiChick04]

Hello,
I'm a 29 yo female. I have a concern about my breasts enlarging, and they are mildly sensitive. (They are not in pain, nor hurt to the touch, but I can tell they are more sensitive.) This is a new development, as of yesterday, July 17. I have taken two at home pregnancy tests (First Response, neither are expired and stored in a place affected by heat & humidity, I administered both tests per the instructions. Plus I did them first thing in the morning, making sure to get as much hormone level as possible.) one on June 7th and July 8th - both tests were negative. I have had my period (heavy flow, cramps, red blood gradually leading to a lighter flow as the week went on - all normal for me), though June's was a week late (hence the first pregnancy test because I did have unprotected sex during a time I might have been ovulating, something I have not engaged in since then, I was also under a great deal of abnormal stress during that time period too ) and July's was right on time.The only other sign of pregnancy besides my breasts would be a mild weight gain - no nausea, tiredness, headaches, cravings, or constantly eating. So if I'm not pregnant? Why are my breasts changing?
I apologize for the length, but I felt the more details, the better answer I could get.
Thank you very much for your time
~ J

[sayley]

I have been going through the same sysmtoms as u and I believe they might hormone related. I will have my hormones check in about 2 weeks. I suggest that u do the same thing. good luck:)

[JoyRenee]

I agree- gaining weight can definitely cause your breasts to be larger.

[smjmekg]

If you have gained some weight that could be the cause of your enlarged breasts.