Hi Alan, having experienced 2 laminectomies, and a triple L4 L5 S1 fusion of the spine, and can say that if you have bulging discs they are most certainly impinging on the nerves including sciatic, this pain is terrible, probably the worst around, the pain sometimes refers to the pelvic area too.
If you have any doubts, by all means have both the bone scan, PSA, and DRE, but I feel you are heading for a bit of work on your back also, if you have the tests, at least you can eliminate the fears of other things affecting you.
If you need any help re back problems, please feel free to contact me. I wish you well.
Regards Mal.