Drying flannel PJ pants?

I'm in college (interior design and fashion merchandising) and I had to take a basic sewing cl this semester. We each had to make PJ pants and I just finished mine today. My professor inspected the workmanship and gave a a 100% on them, but I'm afraid to wash and dry them. I don't know why... I guess b/c they're homemade I feel like they're not as good/sturdy as store bought. Can I still wash them and dry them with a normal load of laundry? I made them too big to allow for shrinkage.