No one here including myself can tell you medically what happened but for what its worth my first miscarriage was a miss. Sadly it can happen so fast, heartbeat one week and gone the next, and for my miss i had no symptoms ending either. I do think its unlikely they got it wrong but obviously I wasnt there. However I actually tested positive for weeks after my first two losses. According to the test i was still pregnant when really i was not.
Grief unfortunately makes you think what if but they genuinely wouldnt have ended a healthy pregnancy on you. The ultrasound is very clear. Ive no doubt someone will pop up saying different but its extremely rare.
When my twins were born, my first boy was stillborn and my second boy lived for 4 days. For weeks after I burried them both, I tortured myself thinking what had I done to cause this. The answer was nothing. I blamed myself for not going in sooner or not realising they were in trouble but the truth is, you have no control over it. And thats the hardest part of all.
But I promise you, once you accept that, the healing does begin, but you need to release yourself from your guilt. You did nothing wrong. It was a cruel cruel thing happened.
I dont claim to be an expert but ive sadly done the rounds on baby loss from one extreme to another. I hope i can give you some peace of mind that it does get better. Not in the "you'll move on and be grand" way but in that you do find peace. My boys will gone two years in November, there isnt a day I dont think of them and some days are harder than others but you do come through it xxx