Pet Scan

hi ladies,
I have a question. I was just scheduled to have a PET scan. Wasn't sure if I'd even be able to get one because I'm very new to my health care insurance and I'm paying out of pocket for it. It's very hard to get ahold of my onc since she's so busy, so I'd like to ask you guys. It's pretty basic and I'm embarrassed to even ask it.....
Does the PET scan do the whole body and the brain? I have incredible pain in my right hip. Will it show anything wrong with the bones as well? Would I need to do a brain MRI or is the PET enough? I'm not covered for herceptin since I've been out for awhile, so I told my onc I'd like yearly scans instead.
thanks everyone!