I did progesterone until 10 weeks. I did it as a 'couldn't hurt' sort of thing - no official need. I was very scared to stop it, but everything came out fine
If it inspires you at all, something similar happened to a friend of mine. She was in her early forties. Did IVF with three different clinics, including Dr T and Cornell. All poor response and bfn's. Was waiting on a donor match, got pg naturally and had a happy healthy boy last spring! Hoping you follow in her footsteps!!