Walked out of the Dr's office today, so embarrassed.

Had an ultrasound scheduled for 3:00 this afternoon due to some irregular bleeding and spotting and they instructed me to drink 32 oz starting at 1:30. Got to the office and it was torture, there were a couple of people ahead of me and I had to ask to go to the bathroom. They agreed as long as I continued to drink water. Kept waiting and waiting and I finally got up and ran to the bathroom. I rescheduled for tomorrow morning, anyone have any tips for holding it in. Help!!!