OK, I'm new to cyclocross & have a question... How much crashing should I expect?

I went to 2 short clinics last week, and in a total of 3 hours, I fell 3 times. I'm not used to crashing. It was my first time riding off road, my first time riding this particular bike, & I had just lost my bike shoes, so I was temporarily stuck riding in sneakers. Also, turned out the rear brake didn't work. So, I'm assuming that it will get some what better, but I'm just wondering how much this is just part of the cross experience.

I loved it & had so much fun, but how much crashing/falling is typical? I've got one huge bruise on my hip, and a few scrapes, so not much damage... but I'm not a kid by any means & am getting to an age where I appreciate having all my joints work.