When will I see noticeable results?

Just finished my 12th OTF class this morning. I am loving it! I wasn't a workout newbie when I joined, but this has upped my intensity a bunch. I also was doing a terrible job incorporating strength training. I am not expecting to suddenly lose weight, but when did you notice improvements in your body composition? I would love to have more definition in my arms and upper back, especially. Currently on the Elite plan of 8 classes per month.