I completely understand where you are coming from and unfortunately it is not an uncommon experience. I do not understand why so may Obstetric Providers blow it when it comes to the empathy part of this field AND make assumptions that are incorrect. Not too long ago, I saw a patient with your exact story. She was told she had a miscarriage and that is what everyone assumed. She then showed up in my clinic with an 'undiagnosed pregnancy' at 28 weeks. Now that was an interesting visit! Sometimes I feel like I continue to participate in this site just to do damage control for all of the bad care and advice that patients get. With regard to your situation, the Providers involved were in violation of my 5th rule of Obstetrics: "Never assume non-viability". They made the assumption without ever considering that they were just looking at an early gestational age than they thought. To prove that point, so far, you have not miscarried, you are not bleeding and you still feel pregnant. This would have been so easy to sort out with serial HCG levels (if they did those let me know the results). But in response to your answers and to address some of your comments, here are some thoughts:
1. I agree with Dr. Norm - your first scan puts you at closer to 4-5 weeks. A scan a week later (at less than 6 weeks) would still not show a heartbeat. This is where they made their first mistake in assuming it was a miscarriage. They could NOT have known that at that point.
2. Is it twins? - well that is possible and will be sorted out with future scans. It might be the reason why you are having pregnancy symptoms slightly earlier than the average person
3. Cycles >28 days long - yes there might be enough variation in when you ovulated that you were a week less far along than you or your Provider thought - that would make sense. If you have a longer cycle, it probably means that you ovulated a bit later than cycle day#14.
4. Tilted uterus - yes, if it is tilted backwards it can make the vaginal scan more difficult because the sound waves are going through the cervix and more of the body of the uterus to get to the sacs. Often the images are not as good / grainier
5. No scans before 8 weeks - this is silly. There are plenty of patients in whom we have no idea when their last period was - I wonder what they do in those cases? Yes, the ideal scan for dating is about 7-8 weeks, but in many cases you just do not know how far along you are (and that is where HCG levels can be helpful)
6. Hackneyed - love that word and I am going to use (but I won't overuse it)
So, yea you might have a miscarriage as about 15% of pregnancies miscarry. But if it is NOT a miscarriage, you are probably not going to return to that Provider - what else are they going to be wrong about? The right answer is to tell you "I think that you are slightly earlier than you thought. We should repeat an ultrasound in about a week. In the meantime it might help to sort out what is going on by checking an HCG level". Most people get the HCG level drawn and any future confusion can be sorted about by repeating it and seeing what it did over time.
Does this help?