It's because if the pg is not going to work out, they don't want to prolong it any longer than necessary for your sake. Prog. supplementation can keep your body thinking it is pg for a long time after a baby has actually passed on, so I think the mindset is that if the pg is not working out, then it's best to let nature take its course, because the sooner it does, the sooner you can TTC again.
I'm sorry tho and still hoping it works out for you. :heart: