Hi Beatriz, I'm sure others will give their experience too, but while we're waiting I'll give mine. I was put on an exam table in the Dr.s office. They gave me a couple of drugs that I do not remember what they were. One was supposed to make me "forget" the experience since they cannot deaden bone. I was told I would not remember the time period therefore, I wouldn't remember the pain. That was partly true. I do remember the Dr. straddled me and put a drill bit in my hip bone. I remember him asking me if I grew up on a farm, why? I asked, he said because I had real tough bones. The next thing I remember was being in an elevator in a wheel chair, looking up at my wife and asking her where are we?
So it was a strange experience for me, but wasn't bad, not as bad as several others along the way.
I wouldn't worry too much about it, a fairly simple procedure, for me anyway. You should do fine.