Good to know to see a dr that was monitoring your blood. It’s seems like so many doctors prescribing these high risk medications simply to receive a benefit from it, while patients are left with the side effects and long term negative effects.

Platelets counts are usually at the high end of normal with osteoporosis and can be lowered to the abnormal range by the use of Prolia. It is good the md is tracking yours.

Many physicians don't use markers for bone loss CTX or gain PINP. Some don't believe them reliable. Most insurance policies won't pay for them. They are expensive and have to be sent to a specialty lab. The endocrinologist I see doesn't use them to determine treatment, but orders them for me.
The lowered blood counts are likely from the osteoporosis. Prolia will likely restore them. And you might use those counts as evidence of whether the drug is effective.
I would be wanting a bone density after a year. Sometimes physicians don't want what we want. Othertime we are stopped by insurance denials. Paying for the test isn't terribly expensive(@145$) if you don't have it done at a hospital.
There are patients who have taken Prolia for two years and have no gain. But there are even more patients who have taken Prolia with great success.