I RECENTLY TESTED NEGATIVE for coronavirus. I was told instead it was probably a “viral upper respiratory infection,” which meant spending a few days married to my nebulizer machine. But now reports of false negatives have me paranoid, wondering if I have a false sense of security.

It all started a week ago with a cough, which I dismissed as asthma. Then came the body aches, which I attributed to hitting my thirties and bleaching the tile kitchen floor on my hands and knees. Then the nausea and subsequent vomiting, which I figured was a result of hitting the quarantine cheese too hard without a Lactaid pill. I couldn’t taste my coffee on Saturday morning, but just thought it was just the crappiness of the emergency stash of old grounds I had in a cupboard.

But the fever and chills set in, up and down for six days, and a cough that went from dry to bloody by Sunday. I’m usually cavalier about illness, since respiratory infections happen so often for me. But when a new symptom, chest pain, set in Monday, I called my doctor. She called back within a few hours, went through a list of questions, and immediately sent me to Mass. General Hospital’s emergency room. There was an EKG, a chest scan for pneumonia, and flu swabs, all coming back negative. There was a nausea pill to stop the vomiting. Then came the swab up the nose for COVID-19. Less than 20 hours later I got an email  —”negative.”

But now medical experts are worried that close to 33 percent of people testing negative for the coronavirus are actually infected. As officials rush to “flatten the curve,” accelerated testing capacity is also throwing in some incorrect results, which lead people to believe they don’t have the virus, and keep them from quarantine.

A primary care doctor in New Jersey experienced that problem when swabs run through a Quest Diagnostics Inc. test kit came back negative for a health care worker, only to have it come back positive at a later date. Her concern — the person came in contact with many people after testing negative. The ramifications for medical workers, who are on the front lines of helping others, are even greater than for those of us working from home.

“Our materials for providers, including our test reports, make clear that while these tests are designed to minimize false negatives and false positives, such results can occur,” said spokeswoman Wendy Bost to the Wall Street Journal.

Similarly, LabCorp told the paper that a “negative result does not definitively rule out infection.” Accuracy, a spokesman said, can be affected by how the specimen is collected, and how long the individual has been infected prior to testing. Both LabCorp and Quest Diagnostics are conducting tests for COVID-19 in Massachusetts, with roughly half of all of the tests processed so far going through Quest in Marlborough.

Quest told the Boston Globe that while the tests are “considered generally accurate, no lab test is 100 percent perfect.”

The US Food and Drug Administration relaxed requirements for testing companies in late February, allowing labs to start testing without approval and submit studies later. The FDA said this addressed the need for more testing, a key priority. One recently approved test delivers positive results in five minutes, and negative results in 13.

In a harrowing local tale, a pregnant woman tested negative initially for coronavirus, but then positive when she was tested again at Mass. General Hospital’s emergency department. Her husband, who is critically ill with COVID-19, was only tested after he was rushed to the hospital, and is now in a medically-induced coma, intubated on a ventilator.

Dr. Larry Madoff, medical director of the Bureau of Infectious Disease at the Massachusetts Department of Public Health, said the test issued by the Centers for Disease Control and Prevention is very sensitive in detecting the virus, with a sensitivity of greater than 95 percent.

False negatives are the medical community’s worst kept secret, and something that hasn’t really turned heads as public officials like Gov. Charlie Baker seek to get as many symptomatic people tested as possible before the predicted mid-April surge of patients in hospitals. Our medical system doesn’t currently have the capacity to run swabs twice — it’s hard enough for many to meet the qualifications for even one test.

Dr. Harlan Krumholz, director of the Yale New Haven Hospital Center for Outcomes Research and Evaluation, outlined his concerns in a New York Times op-ed, saying anyone with coronavirus symptoms should assume they have it, even if they test negative.

“The best the Centers for Disease Control and Prevention can say is that if you test negative, ‘you probably were not infected at the time your specimen was collected,’” he wrote. “The key word there is ‘probably.’”