What Causes Swelling And Pain In Lymph Nodes With Mild Headache?

I have been havimg painful lymph nodes for about a week. I have not had an infection nor cold. Swelling and pain are in arm pit of one arm and swelling and pain at lymph node at my collar bone whoch seems to be causing mild headache. I have had mammograms in the past with biopsy for lymph nodes in breast area (benign)