Pilots who do not wish to carry out a practice emergency but only wish to confirm their position may request a ‘Training Fix’ on 121.5 MHz.
Confirming your position and not being sure of it are two different things. :
a) I'm pretty sure that town is X, but I think I'll check and confirm it - confirming your position.
b) Things don't make sense; I'm really not sure where I am, but I knew where I was five minutes ago, so I can't be too far off course - being unsure of your position.
OK, there may be a grey area in between sometimes, but not usually.
After your comment on another thread about taxiing fast enough to test your ASI (I believe it starts at 40 kts on a C150) and this comment, I'm getting a bit worried about you.
The ASI on our C150, when working, will move at slightly faster than normal taxiing speeds - certainly way less than 40kts. So believe what you like and worry if you like, and don't let the truth get in the way.