Lost my Invisalign retainer on a weekend? What to do?

I completed my Invisalign treatment ~a month ago (end of February). I'm waiting for my retainer trays to come in. In the meantime, I've been wearing the most recent/last trays diligently. I lost my top retainer tray on a Saturday. IDK what to do now. The dentist is closed till Monday, and I don't have my second most recent trays. What should I do? Am I okay until Mon? Even then, what do I do? Can I pay to expedite retainers? It's been over a month now, shouldn't they be ready? I'm in panic!