Interim police Chief Rodney Bryant also spoke at the microphone.
Bottoms told MSNBC on Monday that she got tested because her husband had been sleeping a lot since Thursday.
“Which is just not like him,” she said.
Bottoms said she and her family had been diligent about washing their hands and wearing masks.
“I have no idea when and where we were exposed,” she said.
Bottoms reiterated those comments on CNN but added that she had experienced very mild symptoms, comparing them to seasonal allergies.
According to an administrative order signed by Georgia Department of Public Health Commissioner Kathleen E. Toomey last month, anyone who comes within six feet of an affected person for 15 minutes or more will have to quarantine themselves at home for 14 days.
The news conference scenario can be low-risk if proper precautions are taken, according to Emory University infectious disease expert Dr. Marybeth Sexton. She said it was unlikely most attendees of the mayor’s news conference were exposed as long as they were wearing masks.
The CDC defines exposure as at least 15 minutes of face-to-face contact with a COVID-19 carrier when neither party is wearing a mask.
According to Sexton, it is also unlikely that the interim police chief could have been infected from speaking into the same microphone as Bottoms.
“Surface contamination is thought to be rare,” Sexton said. “You would have to put your hand on the microphone and then in your mouth.”
As a precaution, the fire chief has opted to self-quarantine pending the results of a COVID-19 test.
MORE: Atlanta fire chief in quarantine, awaiting COVID-19 test results
Bottoms will have to isolate herself and cooperate with state and local public health personnel to identify and locate those she came into contact with two days before her positive test sample, according to the order.
She may also have to provide a list of locations she visited during the time she might have potentially transmitted the disease.
Violation of the order is considered a misdemeanor.
In interviews on CNN and ABC’s “Good Morning America,” Bottoms said she believed the state reopened too aggressively. Despite Atlanta’s phased reopening plan, COVID-19 cases have surged recently in Fulton County along with the rest of Georgia.
As Bottoms has tried to manage the COVID-19 pandemic and unrest over police brutality here in Atlanta, she has steadily emerged as a legitimate contender to be presumptive Democratic nominee Joe Biden's running mate. She is often mentioned as a potential VP pick undergoing vetting from Biden's campaign.
A spokesman for Bottoms didn’t immediately answer a question about how the mayor planned to govern the city while isolating herself from others.