Thankfully, you remembered to come here with your question. We all have those moments where things just seem to slip past us. It happens to me all the time, but I just attribute it to my age. Don't worry, though. You can call the friendly Cast Members at (407) WDW-STYLE or (407) 939-7895 and they will be able to retrieve your reservation by your name.
Let us know if there's anything else we can do to ease your mind.