Progesterone and baby aspirin

Doctor wont prescribe progesterone till positive test— I hear most say it’s only beneficial starting at 3dpo and it’s got me feeling pretty defeated. Can it still be beneficial if started same day as positive? Any success stories? Trying to prepare myself. Also I just ovulated— for baby aspirin when did you start and how often did you take it? Thanks.. my OB isn’t the best but if I conceive this cycle before a change to see an RE I wanna give this cycle its best chance of being successful even with my doctors reluctance to use progesterone post ovulation. I’ve had 4 losses