Anyone experience extreme fatigue with BCG Treatment?

My daughter has mixture of high and low grade bladder cancer. She had 2 TURBT’s and has just completed the first 6 BCG treatments. Then had a scope and Scope showed more low grade cancer has come back but Dr said he believes it is working. She is SO TIRED and is two months out from last BCG treatment and getting ready to do the second round of 3 weeks and then wait a few months for another scope. Her Dr acts like if she’s that tired it must be something else. Was anyone else extremely tired like this even a few months after bcg? Also he is not requesting ct-scans, etc. i would think with her complaints he would be all over this. Im terrified. He said it is not in the muscle just from scope. . Thank you to anyone for any help or comments you can offer. We are going to a large cancer and research facility so i would think he would be a good dr?!