No. I can't imagine an air invasion making it to the continental USA without first running into the USAF.
As for a land invasion, they would have to come in from the north via Canada, the South via mexico, or over large oceans on the East or West. Hard to imagine meaningful land forces could be mobilized on the north or south unnoticed, or quietly make it across the atlantic or pacific.
There's stuff to be concerned about. What you raised isn't worthy of serious concern.
We shall see what happens.