Tamoxifen/Herceptin back pain.

nicolajane1100

I was diagnosed with breast cancer in January 2013 age 41. I had the lump removed in February followed by four months of Chemo (every 2 weeks) I started with 4 sessions of AC followed by 4 sessions of Taxol. I didn't have a clear margin after the first op so I have just had a bilateral mastectomy, with reconstruction using a DIEP flap. I am also having herceptin every 3 weeks for a year plus on Tamoxifen for 5 years. Since starting Tamoxifen I have had terrible lower back pains, worse at night. Could this be the tamoxifen? Anyone else experienced this??