That could really be a lot of things! Are the lumps moveable under the skin? How old are you? The three main causes of breast lumps are:

Fibrocystic changes can occur in either or both breasts. These changes are common in women (especially during the reproductive years), and are considered a normal variation of breast tissue. Having fibrocystic breasts does not increase your risk for breast cancer. It does, however, make it more difficult to interpret lumps that you or your doctor find on exam. Many women feel tenderness in addition to the lumps and bumps associated with fibrocystic breasts.

Fibroadenomas are noncancerous lumps that feel rubbery and are easily moveable within the breast tissue. Like fibrocystic changes, they occur most often during the reproductive years. Usually, they are not tender and, except in rare cases, do not become cancerous later. A doctor may feel fairly certain from an exam that a particular lump is a fibroadenoma. The only way to be sure, however, is to remove or biopsy it.

Cysts are fluid-filled sacs that often feel like soft grapes. These can sometimes be tender, especially just before your menstrual period. Cysts may be drained in the doctor's office. If the fluid removed is clear or greenish, and the lump disappears completely after it is drained, no further treatment is needed. If the fluid is bloody, it is sent to the lab to look for cancer cells. If the lump doesn't disappear, or recurs, it is usually removed surgically

Do any of these sound like what you've found?