Shoulder pain for around 3 weeks - I thought it might be the alendronic acid but GP thinks my prostate cancer has gone to the bone. Waiting for x-ray

Having had pain in my left shoulder for around 3weeks I have been to see my GP ,I thought it was likely to be caused be alendronic acid but My GP thinks possibly cancer has gone to my bone . I have read about alendronic acid causing joint pains but Dr thinks as it's only one joint it's not likely. Anybody have any views I am waiting for x-ray at present