You may have a growth which is full of fluid. These are cysts, and they are not cancerous. You may get cysts, especially in the last two weeks of your cycle or as you approach menopause. It is not necessary to have this done, but check with your doctor. If you become familiar with certain lumps in your breasts each month, and you notice no changes, there's little room for concern.
Cancerous lumps are usually hard and fixed.
If you find a hard lump that doesn't move around, see your doctor. However, keep in mind that 8 of 10breast lumps are discovered to be harmless when doctors check them. The important thing is to get to know your breasts. Breat cancer does not alays show up as a lump. It may show up as a rash, discharge from the nipple, or as puckering.