I can understand the fear of confrontation. At the same time, your time and your health and recovery are important. If this has become a pattern then clearly it's something that needs to be addressed. Maybe it's not the therapist's fault (i.e. being forgetful). Maybe it is the scheduling system. If that's the case then the clinic needs to fix it, especially because it's probably happening to other people as well. We depend on our therapists and we need to know we can count on them.

It can be hard, but I would encourage you to try to bring it up in session. Even if you don't feel comfortable "confronting" the therapist, you can still approach it. "I wanted to ask something. There have been a couple of sessions now that haven't happened. I'm not sure if it's a computer thing or something else, but it has been difficult on those days when we were scheduled and couldn't meet. Do you think there's anything we could do together to make sure that sessions happen when they're scheduled? Do you think we could do e-mail reminders or something else? I really love my work with you and I find it helpful. I want to make sure we meet when we have scheduled sessions."