By first gyn, if you mean speculum insertion, I was 20, and had to go for a complete physical before starting a particular program at school. I did not enjoy it at the time, but have since fantasized about it a lot.
I had had breast exams from age 12 or so when I developed, throughout my teens. I had also had external pubic exams. These were at a general family practitioner. Therefore, I assumed this physical would be the same as those. It was at a general practitioner as well, but a new doctor in a different town.
The nurse glanced over my chart questionnaire and said that since I was sexually active I would need a pap. I had no idea what that was. She told me to get completely undressed and put on this little paper gown to open in the front - she repeated that a couple times - I figured they must have had issues with people leaving their clothes on under it or something. She gave me a paper lap blanket for the bottom half. She told me I could just sit on the table til the doctor came in.
The doctor was a very nice looking middle-aged male, which mortified me at that age (yes I'd been active, but only with one guy my age). I remember being completely horrified that he was going to be looking at me naked. He did all the usual exam stuff with me sitting there, then he opened the front of the paper gown to place the cold stethoscope on my skin - back and front. It was all very professional on his end, but I was freaking out inside. He had me interlace my fingers and put my hands on top my head, and did a quick breast check with me sitting up, before having me lie back to do a more thorough one. I have never, never been able to get that out of my head (not that I really want to). That part I actually enjoyed.
Then came the scootching down to the end of the table and out came the stirrups, and he asked me to put my feet in them and drop my knees open. I truly thought I was going to die of embarrassment. I remember him saying, "You're going to feel my fingers touching you", which about sent me over the edge. He did a quick external, very professional, but felt so nice I wished it would continue (and does in my fantasies). But then that damn cold speculum was shoved in and cranked open, and I hated it. It did Not feel good in the least. Fortunately it was over very quickly, and that was the end of it. I also remember being very embarrassed to look at him when he came back in after I was dressed.