Sadly my girl isn’t pregnant but I have used bellylab for all my initial testing and it has been accurate every time. The directions and video are very detailed and if you take the time to read and watch it is hard to make a mistake. I do recommend having an assistant so the initial surprise at the poke doesn’t pull your pups head from your grip because you can miss collection if you let go of her lip. But with a little help it is no big deal😃