Greeny, you probably know that an agent is bound by law to pass on all offers. Your "cheeky" bid will have been logged. They also know what your best bid would be.
The agent will keep you "in the loop". If the Saturday bid is better than yours, that would be the end of the story. If the bid turns out to be unsubstantiated, then the agents will get back to you like a shot.
You must wait to hear from them. To them, you are a good fallback. Your best bid may not be enough of course. You are in a good position. Let the agent sweat it out ;o)