swollen lymph nodes and low WBC count

I'm not sure where to post this, so mods feel free to move it to another forum. I have been sick lately--diarrhea, hives, night sweats, general achyness, swollen lymph nodes in my neck. I went to the doctor and they ran some blood tests and said my wbc count was low-3.5 Any idea what could be going on? All symptoms are gone now except for the swollen lymph nodes. They have me going back for more bloodwork in a few weeks. The swollen glands are hard and only on one side of my neck(under my ear and further down my neck.)