Unless she's taking the BC for health reasons (which she should've disclosed to you.....and shouldn't have come as a shock), I really think you have nothing to talk about more than, "this isn't working for me, I'm staying in a hotel until I can secure more permanent lodging."
And then LEAVE.
And it's entirely possible that she's on them for legitimate reasons, but she could have easily volunteered that information. When we picked up the prescription during a shopping trip, I didn't know what it was and casually asked her, since I knew she had been to the doctor. She said it was to prevent an "infection", since she had just had a small procedure done. It was later I realized what kind of pills they were.
Ex Rzrback Me 43 Her 44 D11, D15 T21, M19 BD 9/9/2014 Piecing
Sometimes if you want to see a change for the better, you have to take things into your own hands - Clint Eastwood