Indeed, it wasn't just me. The news confirmed that what I had experienced was indeed an earthquake. As I expected, the epicenter was relatively close at 110 km (about 70 miles) from Jakarta, specifically at 75 km (46 miles) northwest off the coast of Indramayu in West Java, at the depth of 286 km (178 miles). While it was quite devastating at 7.4 on the Richter scale magnitude, the fact that it was occurred deep under the ocean dampen its impact tremendously. No casualties and no significant material losses reported so far.
Since the quake occurred a day after Jakarta provincial election, there were comments made that it might be a bad omen for future administration of the governor-elect, Fauzi Bowo. I didn't vote during the election day since I wasn't registered due to the error in KPUD's (the commission for municipal election) part.