I would not speculate very much as to why your WBC is dropping. Of course it is a common thing to see WBC drop for a person dealing with any of a number of diseases or treatments for those diseases. However, from reading your query it doesn't sound like you are aware of any thing. What was the occasion that you received a Blood Count test in the first place? If you are not seeing an Oncologist then I would suggest that you do so rather quickly. If you are indeed seeing one and he/she doesn't see any reason for the drop, then I suggest that you get a second opinion. Much better to find the cause sooner rather than later. Best of luck to you.