VANCOUVER -- As thousands of people in B.C. are under public health watch because of COVID-19, a family doctor is reminding people that testing doesn't always offer a complete picture.

As of Monday's COVID-19 update, there were 10,139 people under public health surveillance in B.C. after being identified as a close contact of someone who has COVID-19. Family physician Dr. Rhonda Low explained to CTV Morning Live Tuesday that even if a close contact tests negative, they still need to be cautious. 

"Your COVID test only gives you a snapshot for that moment in time," Low said. "So if you're negative today, that doesn't mean that you won't be positive tomorrow."

Low explained COVID-19 has a two-week incubation period. So, for example, if someone found out they were exposed to someone with the coronavirus, then tested negative a few days later, that doesn't mean they won't get the disease. In fact, they're still at risk of exposing others to it.

"That's why it's important to realize that testing is not absolute and it doesn't mean that you're safe," she said. 

"It's just one of those steps along with self-isolating, wearing a mask, social distancing that can help you decrease your chance of getting the virus or spreading it to others."

In other words, Low said, there are still precautions people should take even if they test negative after being exposed to COVID-19. 

"The type of exposure is key. So if you have been direct contact with someone who's tested positive, for more than 15 minutes in a day, you're at risk," she said. 

"Even if you test negative … public health guidelines ask that you self-isolate for 14 days to avoid spreading it to others because it could take you a week to come down with symptoms."

COVID-19 incubation

Low also explained that while there's a new testing option available to adults instead of the dreaded nasal swab, it's not necessarily more pleasant. 

Last month, health authorities began offering a saline gargle test, which was previously only available for kids. Anyone who takes the gargle test can't eat, drink, smoke, chew gum or brush their teeth for an hour beforehand. 

"For my adult patients who have had the misfortune of having to go do both … they tell me in the end they prefer the swab because it's quicker and the salty gargle isn't all that pleasant to taste either," Low said. 

Even though neither option is pleasant, if someone does develop symptoms, Low said they should certainly get tested again. 

Dr. Rhonda Low's comments were part of a four-minute interview. Watch the full interview in the video player above.