How do I ask if/when I am going to be let go

Hi nannies,
I Have been a nanny for the family I am currently with for almost 2 years. Recently, I saw an application and a letter from an Au pair agency on their countertop. I was not being nosy, just noticed that it was getting sopping wet from when the mom had done dishes that morning, so I went to move it and it of course caught my eye. The words "AU PAIR" were written in capitalized, red, bold lettering. I was under the impression I would be with this family for 3 more years (the youngest just turned 1 y/o). I fear now that I will be out of a job a lot sooner than I thought, bc it seems they're going the live in route. I honestly don't trust them to give me ample notice, so I'm freaking out. How do I bring this up/address my concern without sounding like i was being nosy, etc???