Two bathrooms have a total of 3 outlets. They all stopped working at the same time. How can I fix them?

I checked the breaker box and everything is okay. This happened once before several months ago. A coulple of days later, they all worked again. Is there something simple I can do to save the expense of hiring an electrician? They are not gfi outlets. There are no reset buttons on the outlets. Where could the gfi outlet be? I can't find it in the garage anywhere. It is not where the main breaker box is.