lumpy breasts..self exam

Hi everyone.  First I'd like to say...so glad to have found you.  I have a black discharge coming from my right breast.  Noticed it on Fri night.  I've been obsessed w/checking this breast for some reason the past 6 mo. or so.
How can you tell the difference between "lumpy breasts" and a real lump?

[Cleveland Clinic]

Dear jen59847:  Many women have some type of nipple discharge or fluid when their breasts are squeezed or sucked, and its normal. Squeezing the nipple sends message to the brain and the pituitary gland responds by increasing prolactin levels, which in turn produces discharge from the nipple.  The discharge can come in a variety of colors - gray, green and brown as well as white.  Some women are more prone to more discharge including women on; birth control pills, certain blood pressure medications or on major tranquilizers.  These medications increase prolactin levels in the body.   There are also certain life periods when a person is more likely to get discharge than others: there may be more discharge at puberty and at menopause than the years in-between. The time to worry about nipple discharge is when it’s spontaneous (comes out by itself without squeezing), keeps on happening, and is only on one side.  If it is clear and sticky, like an egg white, or bloody.  If these conditions exist, you should have it checked out by your doctor.  

In terms of self breast examination, the key is to be familiar with how your breasts feel.  Many women have breasts that feel lumpy and this can be quite normal.  The usual recommendation for breast examination is to pick a time each month – should be the same time with respect to your menstrual cycle as there can be breast changes at different times of the month.  After a while, you will become familiar with how your breast tissue feels and will be better able to recognize a change or new lump.  In any case, you should still have an annual breast examination done by a professional (doctor, nurse practitioner).