We had a blood test on our best Angus heifer... said it was positive. She never did have a calf and we turned her into steak.
We had a vet on site this morning he was helping with some dehorning, AI, and so we had him preg check one of our heifers that is supposed to be due in May.
I would have swore she was open but he said she's pregnant but the calf is small so some people might not have noticed and thought she was open.
I don't mind paying to preg check expensive cattle.
If she was positive on the blood test, she WAS pregnant... but she lost it somewhere along the line. Spontaneous abortion/miscarriage is more common than one might think, especially early in pregnancy. On our dairy, we kept pretty good records, and it was a fairly common "anomaly" for a cow to not "come in" for her next anticipated heat cycle, but then to be back in heat like halfway through to the next one.... all that means is that she did conceive, but lost it shortly after, and then went right back into cycling again.
Beefgirl, when I was trained, they had the reproductive tract of both butchered heifers and cows there for us, so you could actually SEE what you were working with as you manipulated the cervix. While still not the same as that of a live animal, I think that helped the learning curve quite a bit initially. Beyond that, I'd suggest that you relax, try not to get nervous, probably best to be "by yourself"... so you don't have the pressure of onlookers you need to impress, etc.
I wouldn't suggest "practicing" on your young replacement heifers though... better to practice on some that you DON'T intend to keep as breeding replacements for that, IMO, especially if you're going to be wanting to breed them anytime soon. It IS possible to do some harm to them, if you're not careful enough as you "practice"... they'll likely heal up just fine... but I'd use something that I wasn't hoping to get bred, and for sure not any that I would be wanting to breed anytime soon.
My cousin and I both took the same course at the same time. He always seemed to have a bit more "trouble" than I did in getting through the cervix, more so on heifers. I think he was just in too much of a hurry, and he'd then try to rush it, or maybe "force it more"... you could visibly see his frustration... and of course, it was ALWAYS the animal's fault... I expect that lots of times, he'd just give up and inject the semen anyway. He did have a lower first-service conception rate than I did... in the same herd. Over time as he became more experienced, his conception rate improved though too. It's mostly just a matter of relaxing, taking your time, being "gentle", and not letting yourself get worked up and frustrated, regardless of how long it might take you to "thread that needle" properly.
Good luck!