Greater Sydney's lockdown is slated to end on July 9, but authorities have not ruled out extending restrictions for residents.
The original time frame for the lockdown - which also includes the Blue Mountains, the Central Coast, Shellharbour and Wollongong - was to run for two weeks from 6pm Saturday 26 June.
This 14-day period was designed to limit the spread of the virus in highly populated areas, and to give contact tracers more time to link how community cases were transmitted.
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But now there are some concerns about whether the lockdown will end as intended on July 9.
NSW's Chief Health Officer Dr Kerry Chant has refused to rule out extending it, saying she does not have enough data to make a recommendation on whether restrictions should ease at the end of the week.
"I'm making no comment until I've looked at all the data," Dr Chant said.
"Every day brings a new set of data and a new set of challenges and what we think in the morning can change in the afternoon.
"I'm really pleased to see that we've had some people come forward for testing over the weekend, which has allowed us to link unlinked cases and the more certainty we have that we have tracked down every single case of transmission, that really does provide us with a lot more confidence in advising government."
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There is no general consensus on how many cases NSW needs to register before lockdown will lift, with authorities saying the method of transmission and the mobility of positive cases being more important than the headline number.
"The NSW Government will assure the community that we will provide a certainty on the way forward and we just need to wait for the experts to be in a position to be able to give us that definitive advice," Premier Gladys Berejiklian said.
"You would expect us to already start planning, which we have.
"I can confirm my colleagues and I have started planning for various contingencies and we are looking forward to receiving the health advice in the next few days but we need to make sure the data we rely on is current and the risks we anticipate are fully considered."
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Ms Berejiklian said the fate of lockdown rests on the next few days, in which authorities anticipate case numbers to trend lower.
"In the meantime can I urge everybody whilst I've got the last say today the please follow the rules. The next few days are critical," Ms Berejiklian said.
"We want to get out of this lockdown as soon as possible in a timely way. I thank everybody for the efforts to date but please keep at it. The next few days will be critical in our decision making."
You can find out more details about how to book your vaccine through the Federal Government health site here.
