Earthquake?

Last night, Mark was coughing and restless with the flu. Rhoda is house sitting so I thought if I slept in her bed, I would be able to get a good nights sleep. I did fall right asleep, she has a very comfortable bed but I woke up suddenly around 3:00am because I felt the bed move. My first thought was maybe Rhoda came home, or perhaps Darcy came upstairs and was climbing in bed but neither was correct. There was no one in the room with me at all. I know the moving of the bed woke me up. The only thing I can think of is that we must have had a very minor earthquake right around that time. Perhaps it was just on that corner of the house. We have always thought there was something weird with Rhoda's room. In the morning, I asked Mark and Sarah if they felt anything during the night but they didn't wake up at all. I think I'll stay in my own room from now on.