I always go unless I'm ill or some other emergency comes up. For me, it is a commitment to getting better. Cancelling, if to avoid talking or difficult subject matter, would simply slow the process and it is slow enough as it is.

I do have times when I space out my sessions because I'm just in a place where I feel I can do so, but that isn't a last-minute decision; I make those decisions at the time I make my appointments. That would be my in-between space I guess. But I never had hard-set weekly appointments; my sessions varied on day and time depending on my (and my family's schedule), so my appointments varied in space between anyway which I kind of liked because I think it helped me be less obsessive about having to be in therapy every week on such and such day at such and such time.