It is impossible to have an odd number of flipped edges. If everything else is solved on the puzzle and you have three flipped edges then pry one out and manually orient it correctly.
I made a video for fixing the orientation of pieces in pairs:Simple Pyraminx Crystal edge-flip commutator
The way you hold the puzzle does not reflect how easy it is to do that: flip one edge in 3 turns, position the other edge then flip the second with the inverse of 3 first turns. Finally undo the positioning turn.
With only BASIC understanding of commutators doing this 2-flip is really trivial