It definitely sounds like a blighted ovum. The fact that there is still no fetal pole, the hcg is decreasing, and the sac has decreased makes it seem like its not a viable pregnancy. I would wait on the d&c as natural is better but if you dont start showing signs of passing it you may need one. They are more common then you think and i know that wont comfort you now. My first pregnancy was a blighted ovum, found out at this12 week scan. I had no warning except decreasing symptons at 10 weeks. I ended up with a blightedd&c and it went fine. That was a year ago on aug 18. Im so sorry you are going through this. It does not mean there is anything wrong with you. Im now and31 weeks in my 2nd preg
Unfortunately there are no doctors on this forum, just ladies who are, have been or are trying to become pregnant.
I'm sorry you are having to go through this. In my opinion, what you have described doesn't sound very promising. By now you should have a definite fetal pole and heartbeat. It sounds like you are going to need that d &c, however, if it would give you better peace of mind you can always request they do one more ultrasound before you agree to it. Again, I'm very sorry. I know it's not an easy thing to come to terms with, I've had two miscarriages and a full term stillborn myself. BUT, I have FIVE beautiful healthy kids, don't give up hope. Most women will experience 1-2 miscarriages of one form or another during their reproductive years.