KITCHENER -- When a 25-year-old healthcare worker got a bad headache in mid-March, the last thing she thought of was COVID-19.

Petra Kljaic-Rai says she started having symptoms in mid-March, and tried to alleviate her headache with over-the-counter drugs like Tylenol.

"I thought I honestly just had a sinus infection at the beginning, just because of my headache. I had no contact with anyone who has travelled, and I haven't travelled for months, so I thought I did not have it whatsoever," she remembers.

Her family members agreed: she says they thought she might have a common cold or the flu.

But her symptoms continued to develop. Ultimately she experienced headache, fever, chills, body aches, fatigue, dry cough and shortness of breath.

"I actually got tested just because I'm a healthcare worker, I work at a healthcare facility and they want people to get tested who develop symptoms that are for COVID-19," she says.

Kljaic-Rai works in an area where she does not have patient contact.

It was that test that brought back her diagnosis: she was positive for the virus.

"To this day, we're all very shocked and surprised that I have it, and we still don't know to this day where I could've picked it up," she says.

She believes hers was the first community case in the region.

Kljaic-Rai finally tested negative for the virus after getting tested four times over the course of three weeks.

Hers is one of 120 resolved cases in the region.

At 25, she doesn't fall into the highest-risk demographic of the population. After her experience, though, she's warning others to take the virus seriously.

"At the time, honestly when I was getting tested for COVID-19, I didn't take it seriously at all. Just because I'm a healthcare worker, I'm always protected, I always wash my hands, proper handwashing and everything," she says.

"Take it seriously, because it can happen to you."

Kljaic-Rai says she wants people to stay home and to be considerate to others around them.

With reporting from Krista Sharpe