Either it was an Earth quake which would be my first or someone in my resident building was causing a around half centimeter magnitude ground shake of 1.5 frequency for about 5 seconds, at 1:57pm today.
I did check the earth quake watch site very quickly and found a close one in Virginia, 5.8 magnitude. I still had doubt, because my upstairs neighbor behaves like buffalos sometimes.
After another news update, convinced me it was a natural event.
And after a suspected server traffic overload time at NY1, it is finally confirmed.