So far I have only used the "wait and see" method, with minis anyway. My vet does not ultrasound, they have said they can palpate but I am leery of having a mini palpated. I have also heard blood tests with minis werent very accurate. I've considered the weefoal tests, but have not tried them yet. I guess if I were really wanting to know for sure, I would try that but for the most part I just wait and watch. I always write down when mares are in season and when I see them get bred, so far that has worked pretty well for me to determine if they are bred and when they were bred.