I had some side effects from the beginning. Although, I was also on radiation at the same time. It got really bad starting about week 4 and continued through 5 weeks post treatment.
I didn't start pain medication until the middle/end of week 4 under the demands of my oncology nurse. I told her I was not really in pain, just extremely anxious, which turned out to be my reaction to the pain and discomfort I was feeling.
Hope all goes with your treatment and you have a full recovery.