Fibrocystic changes in breasts are very common. The water is in the glands that produce milk after delivery of a baby. There can be water in the tubes that lead from the glands to the nipple too. Both the fluid filled glands and the scar tissue will feel lumpy. This can be hard to tell from non-fibrocystic breast tissue.
All breasts feel lumpy.
It's the glandular tissue and fatty tissue in the breasts that feels lumpy. If they feel lumpier before your period and less lumpy 7 to 10 days after your period, you have fibrocystic changes. Now, if you feel a lump that is harder or larger than the other lumps, see your health care provider for a breast exam. The lump will probably just be fibrocystic scar tissue. Lumps that go away after a period are almost never cancer.