Should I be worried?

I have been experiencing mild to moderate pain in my left breast for about eight or ten weeks. I have been to see my GP who said she could feel a lump (I couldn't); she has asked me to return after my next menstrual period so that she can check whether or not the lump has changed and then decide whether I should be referred to the breast clinic for further tests. Naturally, I'm a bit concerned. However, the literature I have read so far consistently states that cancerous growths are 'nearly always painless'; cysts seem to be much more commonly associated with pain. Is this generally the case? By the way, I'm 31 years old, have two children, aged four and fourteen months, and the onset of my breast pain more or less coincided with stopping breastfeeding my youngest (don't know if that could be significant). There is no directly relevant history of breast cancer in my family, but I believe my maternal grandmother did have it in her 60s.

[CCF-RN,MSN-JS]

Dear Gavagai, This could very well be a cyst.  It makes good sense however, to have it rechecked by your GP (especially since you could not feel it).  In general, a painless lump is more commonly associated with cancer, but following up on a new lump is a good idea.