Minimal sac growth, losing hope..

So I got my 1st (2nd and 3rd) BFP the week of 6/8.  I Should have been almost 6w last Fri.  Had my first OB app due to early due to previous mc on Friday.  Did an internal ultrasound and there is what may be a potential sac - just very very small so really hard to say for sure.  Hcg levels were 1,042.  Had more blood work today. Waiting on the results. Minimal sac growth. I should have been much further along by now. My dr still can't tell me anything definitive other than "you are pregnant." But chances are good that I am or will miscarry (again). Going back again weds for another scan and probably more blood work but at this point I just feel like this is a loss. Majority of my symptoms are gone and I am just waiting....  Anyone ever been in this situation where it turned into a healthy pregnancy?