Lauren, talk to your gym teacher! I'm sure he or she will understand... I had that same problem with going between Art class and Chemistry a couple years ago. they were on opposite sides of the campus, like 1/4 of a mile apart cause the art room is pretty far from the main campus... But my Chem teacher totally understood and gave me a couple mins slack.
I started school today too, I had to get up at 5am! It was soooo hard, I only got like 4 and a half hours of sleep, I am so tired!