Good question, but problematic. The only way to know for sure are CT and bone scans. You do not want to be having those unless you have to. You don't know if you have to until something goes wrong. But how wrong and what is the ' something'.
We just have to trust our instincts, be aware of our bodies and react if something doesn't feel right. When you have been through months of treatment, been poisoned, irradiated and had your hormones reduced to next to nothing it would be more remarkable to feel well, but if you do feel sick(er) or in more pain than usual or start changing colour, trot yourself off to your most trusted medico and talk to them.
It's a maddening situation to be in. We hope all the palaver has been worth it, but there is always a lingering doubt. Time is the only healer for the anxiety that accompanies cancer. Good luck and I hope what ever doubts you have turn out to be nothing to worry about. Marg xxx