From Monday, pupils over the age of 12 are expected to wear coverings in areas where distancing is not possible.
Nicola Sturgeon said there is a 'possibility' guidance will change amid a number of cases among students.
First Minister Nicola Sturgeon will update MSPs on schools as well as any further changes to lockdown.
Group advising Scottish Government says no social distancing is required between pupils.
Scots should get used to wearing face coverings in public 'for the foreseeable future', Nicola Sturgeon said.
ScotRail said free masks would be available for a 'limited period' as face coverings made mandatory from Monday.
The First Minister said she will consider if the recommendation should be made mandatory.
Nicola Sturgeon said the advice is not mandatory and stressed it is not a substitute for following existing guidance.