Already diagnosed with IDC, now possible leukemia

I was diagnosed with IDC back in March, had a mastectomy in April. I finished the 4 treatments of A/C. I was supposed to get 12 doses of Taxol but my oncologist called it off after 9 doses. My last chemo was a month ago. My WBC dropped and has yet to recover. So now, I'm scheduled for a bone marrow biopsy. Of course, I hope that the test comes back negative but I'm still concerned. Has anyone else ever experienced this?