Ive had ultra sounds like that and they do hurt. A year or two ago they thought I had a blood clot in my leg so they did an US. Thankfully I had no clot but they sure slapped me in the hospital on bed rest fast enough. UGH.
I know its hard but please try not to worry. Worry never helps and it just makes ya feel yucky. I know thats easier said than done but just know you have a world of support here.