I'm sorry you are dealing with this. These are NO fun.
I have a 7mm sitting up inside my right kidney too.
Your doctor may be trying one last attempt at dissolving these stones before putting you through Litho. Keep in mind, litho is expensive and requires a type of anesthesia. If you are prego or trying to get prego, the anesthesia may not be good for you.
I have never encountered pain in my legs from any of the 18 stones I have passed. But, I do sometimes get groin/thigh pain with my ovarian cysts (as you mentioned above)
As for the fever - I have had a fever only twice with the stones, and it was because they were passing and causing intense pain. The trauma of them passing can inflame the inside of the ureters. One time, the stone did cause a kidney infection which spiked a fever.
Anyhow - no one can really speak on your doctors behalf as to "why" he isn't moving ahead with the Litho. But, I would suggest you call him and ask. It is an honest question and I would want to know too.