Of course. The karate club has no attendance requirements. You will get more out of the club if you can train more frequently, but if a scheduling conflict prevents you from doing so, you are welcome to join and attend whatever classes you can. Depending on your schedule, you may also consider attending some classes at one of the local dojos to make up for missed classes, which should help you stay prepared for kyu testing. With the club's semester fee, you are entitled to practice free on Saturdays at Sensei Fusaro's studio - take advantage of this!