Could this be somthing eles?

I figured you guys would know the most about this. Here is some history;
I had gone to my GP I was constantly feeling like I had the flu and was extremely tired. My doc did blood work and said my wbc was little too low that I was probably fighting off an infection, and to come back in two weeks to be retested. I did and they were still low. Since they weren't extremely low (I think they were 3. something.) they would just keep an eye on them. they stayed low so I was tested for HIV, Lupus, and MS, all came back negative.

This last time I went in for shortness in breath, night sweats, and headaches, and my wbc count was still low and my dr said I needed to make an appointment with a hematologist. I live in a small town and their office has been very busy, so I haven't got to ask many questions. I have been researching on the internet and so far can't find any other reason for a low wbc count and a visit to a hematologist, besides leukemia or lymphoma. Oh I also have a very enlarged painless lymph node on my neck that my ENT is keeping an eye on. Non Hodgkin’s lymphoma runs in my family.