Is the change a warning sign?

Approximately 3 months ago, I visited my doctor with a painful lump on the bottom of my right breast. My doctor informed me that due to the fact that it was painful, it was probably a cyst. He recommended cutting back on caffeine etc.. to see if it dissolved.  About a month later, I noticed that the lump seemed to have disappeared and the pain was gone as well. However, 2 days ago, I noticed that the lump is back and now there is no pain associated with it. It seems harder, more solid than before. I am 33 years old, had a hysterectomy at 29 for cervical dysplasia, and am terrified at the possibility of breast cancer.  I don't have a "monthly cycle" so I cannot assume the time period of my ovaries releasing an egg. I understand that women my age have dense breast tissue and therefore wonder if my request should be for a sonogram instead?  Thank you for any input.
rwz

[CCF-RN,MSN-JS]

Dear rwz, Although you have had a hysterectomy if your ovaries are intact there still may be the cyclical fluctuations in hormone levels, which could be effecting your breast tissue.  Since this lump does seem to be a change, and has not been examined you may want to bring this to the attention of your physician for further evaluation.  The density of a woman