Not everyone feels entirely comfortable in front of a camera, myself included. If this is you, then you will probably feel nervous about being in the spotlight on your day, which is entirely normal. Firstly, the documentary style will probably work very well for you, as you can forget the photographer is there.
Secondly, a post engagement shoot can be perfect for getting to know your photographer and how the relationship will work on the day, encouraging you to relax, and feel at ease, as well as working through some ways you can really look your best in front of the camera. We can go somewhere that is special to you as a couple, to get images which truly reflect who you are.