I'm sorry but this is bordering on parody to me. The way she would notice it "sooner or later" is by her bleeding on her clothes and possibly even furniture. In what world is it important for you to just know about it and somehow not important for her to avoid that?
> The way she would notice it "sooner or later" is by her bleeding on her clothes and possibly even furniture.
No, many can feel it beforehand, and you notice it when you go to the bathroom before as well, as certain things change their properties slightly, it's not a "nothing" phase and then "floods out of your body".
It's borderline parody how little education there is for males when it comes to things like this.