5yo with knee pain

C

I'd say for the past 2 years my daughter has had pains in her legs. At first she was so young that she couldn't tell me exactly what hurt she'd just point to her leg. I assumed it was her hip because I have bad hips. I had everything checked out and all came back ok. Now that she's 5 and in school and other activities I've noticed it is much worse. On her active days she now tells me it's her knees. Any day she has either gym class at school or dance she wakes up in the middle of the night in such pain that she falls down. It is like clockwork. I give Tylenol and spend an hour calming her back down. I have been in contact with her pediatrician and we've done X-rays which came back normal and they said next step is going to a pediatric orthopedic. Has anyone else been through anything similar? What could it be? I feel so helpless when it happens. 😢