i, personally, took 4 first semester and 5 second semester (one course was pass/fail). However, I was also researching at the Med School for 8-10 hours a week both semesters, so I guess you can call that a class. Usually, freshman take 5 though. It also depends on credits and which classes you take too. For example, if you're taking 15 credits than you're fine even if you have 4 classes, and if you're taking 3 sciences or something, then you're good too with 4.