We brought her to a pediatritian in two states, both thought it was nothing but "growing pains". Her limp got worse, she was in incredible pain for days. She would develop fevers with no other symptoms.
She would mysteriously get better, then a month later it would happen again. Each time it got worse and her pain increased, the limping was more pronounced.
They misdiagnosed her and wanted us to see a specialist for it. We refused to wait a couple months to get an appointment with one and demanded to see someone, anyone else.
We eventually got to see a doctor (not a pediatritian) that at least done their done and ordered proper tests. Unfortunately they found bone lesions. Upon closer inspection they found a primary tumor in her abdomen, the cancer has already spread to her bone marrow (hence the bone pain/lesions and limping).
She's doing pretty good now-- still along ways to go for treatment though.
All in all-- as a parent you need to follow your gut and don't trust everything doctors say or feel. We lost a few months due to poor pediatricians that couldn't do their job (these were pediatricians at well known places).