What did the button look like? The final screen has a big orange button that says "Transmit Returns Now."
When you log in and go to the Tax Home, what is currently displayed there for the status of your return?
If you just recently efiled with successful transmission, it should say "pending." Then up to 24-48 hours later (or often much sooner) would change to either rejected or accepted. Or does it have some other status showing?