I didn't feel it at the office, but some of my coworkers reported feeling a slight shake. It didn't register very high at all, only 2.8 on the Richter scale, and earthquakes at that magnitude are usually not felt at all.
But according to the seismologist on duty at the Geophysics Institute at the Bulgarian Academy of Sciences, “The earthquake was felt immediately below the feet of the Sofia citizens because the epicenter was located slightly south-east of the capital. It was felt strongly in the eastern and central part of the city and the maximum possible degree of impact has been 3 or 4,” he said.
Jodie, cooking in our apartment, also felt nothing.