Pelvic ultrasound

Hey ladies, I’m getting my first ever pelvic ultrasound on Friday, and I’m so very terrified. I’ve never had anything go up my vagina before (a tampon once but I had a mental breakdown trying to do so). I was sexually abused as a child so I’m just very triggered by anything that deals with my vagina. Do any of you ladies have some tips for me to stay calm and collected during my appointment? Also what should I expect? Thanks for any advice you do give!