In a recent copy of Flyer there was a handy booklet from the Royal Institute of Navigation (RIN) on "Visual Navigation Techniques for Pilots". Section 3.10
Uncertain of Position from this booklet provides the answer to your question and also provides guidance on what to do if lost rather than uncertain in sub-section 3.10.3.
Navigation is part of the experience of flying and dealing with the challenges it throws up is part of what makes flying fun to do. Had you thought of having a go at the Top Nav contest to build on and consolidate your PLL skills?
Top Nav | Royal Institute of Navigation --