Hey, I went for an external scan a few months ago.
Before I went for the scan, I actually called the hospital to find out whether it was an external or internal scan. They told me they don't really perform internal ones that much any more. So I went, ready for an external scan.... Had to drink plenty of water beforehand, and was bursting during the scan! The sonographer couldn't see anything. She then asked me if I was alright with her performing an internal scan. I was fine with it, but it was a bit awkward haha, as I wasn't really mentally prepared for it. She told me I had A LOT of cysts, but she did not show me the image - and I didn't ask to see it either, was a bit distraught about being poked where I shouldn't have been. The results were then sent to my GP.
That was about it. Don't worry about it. It doesn't hurt.... That gel they put on you is a tad cold, but that's all. Don't be afraid to ask questions, if you have any.
Good luck!