Cortison shot in hip - new knee pain

I had a cortisone shot 3 months ago in my right hip. It worked immediately and I've pain pain free since. However, the past week or so, I noticed I have sudden knee pain. Sometimes I can walk normally and suddenly when I put weight on my right foot, I have severe pain in the bone in the right knee. I even use a crutch sometimes the pain is so bad. Does anyone know if this is related to my hip condition? I do have a doc appt set up to check this out. Thanks.