Just talk to your professors about it beforehand to see if you can work something out.
In one of my classes, on the first day the professor said that absolutely-positively-without-a-doubt that she wouldn't accommodate your schedule and if you miss a test, then that's your single dropped grade. If you miss two, well you're screwed. She didn't care if you got hit by a bus or had a dozen med school interviews, that was that. Well I talked to her about taking an exam at another time since I would be missing one due to an interview. I asked if she could find it in her heart to make this one exception since I was interviewing at her alma mater UW-Madison. I even added in a "Go badgers, woo!" at the end of my proposal. She let me take the exam when I got back the next week.