Hi Valachira,
I am a pro-e noob so I apologise if I offend you with this basic explanation hehe. I encountered this the other day, I find the detailing in pro-e very long winded so I also import drawings into autocad when I need to.
I tend to save them as DWG files and select release 14, I leave all the options as default. When it comes to scale, you have to make sure the Pro-e drawing is scaled 1:1, otherwise it will import into autocad at whatever scale your pro-e drawing is.
To explain simply, a pro-e drawing scaled at 2:1 will import into autocad at 2:1 rather than using the 1:1 scale of the model
Hope that helps.