Anyone gone through Version?!

So I'm 36+3 and my dr wants to do a version at 37 weeks.. my baby is footling breech and they absolutely will not deliver natural unless he turns/is turned... so my questions are these... does it really hurt? It's my first pregnancy so I've heard it sometimes doesn't work... should I be prepared for disappointment just in case it doesn't work? My baby moves A LOT but won't move head down for some reason.. I've been doing my "exercises" to help him turn naturally but he doesn't seem to want to do it.. I'm nervous and scared of something going wrong with my first baby boy