Look, I understand exactly the place your in.
Unless you can be over 100% sure that you are not going to impregnate her, don't loving do it. Don't rely on her, don't hope, don't try to make do. The only way you can be 100% sure is pretty clear, don't do it.
I know it's something you want, but don't risk your entire life over something that will eventually be solved anyways.
Good luck and I wish the best for you