Despite health experts urging people not to gather with people outside their household, many are already making plans for Thanksgiving.

In fact a recent poll says 40 percent of Americans are planning to gather in groups of ten or more for the holiday, 25 percent of those will not be wearing masks or social distancing. But some think they’ve figured out how to have a safe way to gather: they’ll take a COVID-19 test before the gathering and require others to take one too, the negative test is their ticket to celebrate.

Dr. Alan Williamson, the chief medical officer at Eisenhower Health says that’s not what the diagnostic tool is supposed to be used for, “There’s several flaws with thinking that means that I‘m fine to go ahead and get together with people and not have to worry about social distancing and masks and so on.”

He says often times people use testing without quarantining, get exposed and think they’ll be safe.

He says every test including the “gold standard” PCR COVID test requires a certain amount of virus in your body to be detected by the test and that takes time, “Three to four days on average though it sometimes can be longer than that after patients are exposed and infected with the virus before we can actually test positive.”

A recent study in the Annals of Internal Medicine examined false negative tests estimated that four days before symptoms started you are 100 percent likely to test negative, and when you start showing symptoms the likelihood of a false negative test is not zero but 38 percent.

“It’s certainly possible that you are exposed say on Monday you go your test on Wednesday it’s negative but by Thursday or Friday or Saturday you may actually begin to be physically ill from the disease and two days or so before that you may well have been spreading that disease to others,” says Williamson.

According to the Centers for Disease Control, 50 percent of transmissions happen before symptoms begin. People are most contagious two days before they feel sick and two days after they start having symptoms.

Then there’s those who never show symptoms, according to the CDC 40 percent of infections are asymptomatic.

“They’re the highest risk of getting a false negative test, the patients that are asymptomatic,” says Williamson.

Also there are tests that are less reliable. The FDA has warned the rapid tests or antigen tests are delivering too many false negative results. One study showed an antigen test, failed to detect half of the positive samples. They recommend a second PCR test to confirm the results. But many prefer doing the antigen test because the PCR test requires being processed at a lab and results often take days.

“There’s still a significant risk that a antigen test can give you a false sense of security,” says Williamson.

Bottom line, no gathering is 100 percent safe, even if you test negative for coronavirus.

“We’re trying to find tests that will guarantee us that they are safe and unfortunately right now we don’t have anything that does that reliably,” says Williamson.

In California hospitalizations jumped 30 percent in the last the last two weeks, health officials are asking people to limit gatherings to no more than three households that includes your own, hold your gathering outdoors or in a well ventilated area and keep them short, plus follow the COVID precautions of frequent hand washing, wearing masks and social distancing.

California issued the following non essential travel advisory on Friday:

Travel Advisory for Non-Essential Travel

1. Persons arriving in California from other states or countries, including returning California residents, should practice self-quarantine for 14 days after arrival. These persons should limit their interactions to their immediate household. This recommendation does not apply to individuals who cross state or country borders for essential travel.

2. Californians are encouraged to stay home or in their region and avoid non-essential travel to other states or countries. Avoiding travel can reduce the risk of virus transmission and bringing the virus back to California.

“Non-essential travel” includes travel that is considered tourism or recreational in nature.

“Essential travel” includes: work and study, critical infrastructure support, economic services and supply chains, health, immediate medical care, and safety and security.

Experts Warn COVID Testing Before Holiday Cannot Guarantee a Safe Gathering