Axillary Lymph Nodes/Fibrocystic Disease

I am 24, and have fibrocystic breast disease...I have seen a breast specialist surgeon who did ultra sounds on 2 occassions and has told me the that lumps in my breasts represent fibrocystic changes.  At the first appointment, I also had a palpable axillary lymph node, which was 1 cm and appeared benign (in tact capsule and normal appearing hilum was what she told me).  I was concerned and went back a few weeks later b/c I felt another lump near the first lymph node, but she said it was not another lymphnode and not to worry.  She said to come back in 4 months to be re-evaluated.  In that time, the axillary node as remained palpable and the same size.  My breasts tend to be swollen/tender with my cycles, as they had been previosly.  The day before yesterday, I noticed ANOTHER axillary lymph node on the same side, further into my arm pit and what feels like one on the opposite side in the same location as well, although the one on the opposite side seems smaller.  She told me that the reason I could feel the first one is b/c I'm very thin, so I'm hoping that this second one is palpable only b/c I'm thin as well, but I am absolutely freaking out and am terrified it represents a malignancy.  Does anyone know anything about the chance that a normal appearing lymph node may have actually represented a malignant lymph node?  What about the frequency of palpable axillary lymphadenopathy that doesn't represent malignancy?