No, you didn't dream it! There was a 4.2 temblor this morning at around 4:42 a.m., centered two miles east of Oakland on the dreaded Hayward Fault. It knocked out power in Oakland (poor PG&E, it's been a busy week), and broke the windows of the Safeway on Shattuck and Rose in Berkeley, and at a doughnut shop on College and Ashby (but with no interruption in donut service, they added) -- but in SF, we didn't notice anything other than some shaking, and in San Jose, they didn't feel anything at all.
There's a YouTube clip of Jell-o artist Liz Hickok's Telegraph Hill earthquake above. (Friend of SFist, and we know her sister too!)