No, you aren't losing your mind: that was definitely shaking you felt.  

A 5.8 magnitude earthquake occurred in Virginia at 1:51 p.m., according to reports, with tremors felt as far north as New York. 

The Patchogue-Medford Library was evacuated and will remain closed the rest of Tuesday, library officials said. 

Liz Kircher, 11, was using a computer in the library's young adult section when the quake hit.

"I saw my computer shake and my desk shook," said Kircher, of Patchogue.

Mark Costello, also of Patchogue, said he saw the whole floor shake.

"Whatever it was, it was really powerful," Costello said.

Following the announcement that the library was closing, library director Dina Chrils instructed patrons to quickly shut down whatever they were doing and to return materials in case of a possible aftershock.

Residents across the area are saying it was more than just a little shake that they felt. 

"House was swaying back and forth for maybe about a minute," East Patchogue resident Denise Gleason Hard wrote on Patch's Facebook page. 

County Executive Steve Levy was on the 12th floor of the H. Lee Dennison Building in Hauppauge when the quake hit.

"We had just finished an emergency practice drill less than an hour beforehand," said Levy, noting that the building swayed. "One of the things that went through my mind was that someone bombed the building, and maybe this drill wasn't such a drill.

"But thankfully no one was injured, and this is what you train for," Levy added.

Levy said there have been no reports of injuries in the county due to the quake. 

Police are asking those who wish to report non-emergency incidents resulting from the earthquake, such as downed trees or wires to call the Suffolk County Police Department’s non-emergency line at 631-852-COPS or 911 in the event of an emergency.

You can see exactly where the earthquake struck in Virginia here.