Breastfeeding in public

Jess • Married to the love of my life, totally smitten with our little girl and boy.
We have our first doctor's appointment tomorrow morning for our little one. Having only been a mom for a week, and therefore new to breastfeeding, I'm having a good amount of anxiety about the appointment. 
I'm worried because if we get there and she's hungry, I'll need to nurse her in public that I know a lot of you are comfortable with, but I can't say I feel totally comfortable with that yet so tha makes me anxious. 
Also, if we get interrupted, she's going to be so upset. If they call us back and she hasn't finished nursing, she's going to be crying through the appointment, which breaks my heart. 
I'm just worried that tomorrow is going to include a lot of tears which always upsets me because it makes me so sad to see her crying when I know I can help her. 
Any tips/thoughts?