You shouldn't have to go another 30 days, but just stay vigilant for maybe another week or so, considering some of the items you thought were safe but might not be.
Happily I don't have much mite "experience" either, but it would just be awful to have them reappear or spread after thinking they're gone. It's happened to a number
of ppl that have posted here, so I'm hoping you won't be one of them.