Transvaginal Ultrasound question! Would love some feedback!

I have an ultrasound scheduled in a couple weeks and they said they'll try abdominal but probably have to do vaginal. I have a history of twins on both sides so they wanted to know whether or not that's the case. I'm just wondering is the transvaginal u/s safe or just uncomfortable? They don't have to stick it up too far right? I just don't want to hurt the baby in any way. I would love any feedback on your experiences, preferably to calm my nerves😁😌 I'm just always worried about something hurting the little bb!