C.B.
I'm feeling like the others missed the question - or maybe I am.
I think you're asking how to get her to tell you when she's in pain because she doesn't want to tell you trying to avoid a doctor's visit. Is that it?
If so, I know you told her that she won't get any shots or medicine, but can you tell her what WILL/IS going to happen? Maybe that might help.
Other than that, I really like Tracyxo's idea to watch her with her baby doll to see what is going on with her. You can tell an awful lot about what a child is feeling by listening/watching their play.