Can you get tooth decay under an Invisalign attachment if teeth were not cleaned properly?

I got 22 attachments recently, Just before the appointment I absentmindedly ate a sugary snack. I brushed my teeth very briefly afterwards before leaving the house. During the appointment the orthodontist didn't clean my teeth and I am now worried that I could have bacteria/sugar below the attachments which may cause decay or staining? Is this a genuine concern and can I do something about it? or is it unlikely that bacteria can grow under the attachment due to lack of oxygen etc? Thank you!