OK to take Rituxan?

I just had a very weird conversation with a staff member of the neurology department. I had asked for a copy of my last blood test done on Jan 2. I was told that it would cost me $50, so I said “no thanks”. They wanted to know why I wanted it, and I said that it was to track the IgM levels and white blood cell count. Then they said that IgM levels were not part of the blood test. Instead the monthly blood test is being performed to see if it is OK for me to continue to take Rituxan. They said that they are tracking my bone marrow function and liver function to see if I have a reaction to the Rituxan.
I am stumped as to why they are not tracking IgM levels. I thought that was the whole purpose of the expensive exercise.
I have an appointment with the neurologist in early March and will ask again at that time. But maybe in the meantime I should go pay for electrophoresis myself and get a separate blood test done.
This is very confusing. Does anyone have any thoughts on this? It feels as if the patient should be the last person to know anything.
Thanks for your comments.
Andrew