Hi,
It's really hard to say what is happening,.unless more tests are run by your doctor.
Bone Density Scan,such as you had, shows that you have bone thinning (osteoporosis) which can cause spinal compression fractures.
The pain you are experiencing could be unrelated to cancer,but to find out for sure, your doctor should order more tests,like CT scan, MRI,or a PET scan.
I am sure your doctor will recommend which test you should be having and treat your osteoporosis with medication if the diagnosis is negative for metastasis.
Hoping that no cancer will be found..and wishing you all the best!