If you're really that unsure, I would ask. I thought my entire application to one school was complete. I had sent a recommendation letter via USPS back in November because the recommender did not want to use the online system. I called last week to see why it hadn't matched up with my application yet, as I applied in early January (the deadline was Feb. 1). Turns out, they had put it into a file for people who send some materials, but never actually apply.
If I had not called, I am not sure this would have come to my attention. It never hurts to be a little paranoid (but only a little). Good luck.