Hi Mary: I'm sure this has happened to many others on numerous occassions. Planning ahead, kind of like a budget, is only a plan, and can subject to many factors that interfere with it's fruition (Life is the thing that gets in the way of our plans - John Lennon). Even with current planning, there can be planning interrutions, delays, or conflicts that challenge getting through all of the material, covering the intended course content, or coming up short. So, it's always a bit of trial and error. Good teachers will make what, to us is a planning conflict, seem like it was all a part of the plan to start with. Regards, Barry