Exceeding monthly monitoring totals for 1 monitor?

I have a single monitor, from 1 region running hourly on a free account. For the second or third time this year I have received a notification that I have exceeded my 1000 call limit and monitoring is stopped.

"Dear Monitors User,
You’ve used all of your free monitoring calls for this month. "

I don’t see how this is possible to do unless monitoring totals include something additional to the the monitoring. Do other actions like saving collections count against monitoring call totals by any chance?