9 days until first OB appointment

So last week my wife and I went for our first ultrasound, she is 6 weeks 5 days,  with this fertility place we have been going to for the past year. They said they needed to confirm it as a "viable pregnancy". Those are two words no one wants to hear. My fears since we found out K was pregnant was "I hope she doesn't miscarry", well I think everyone has that fear, and my second was "oh god it could be twins, what do you do with twins, OMG OMG OMG"! That is just to put it lightly. Don't get me wrong we would have made it all work out and would be happy as hell but for first time parents one is more than enough. 
As the doctor enters the room she asks K how she feels and what her HSG numbers were. The doctors first reaction was that it might be twins.  I can't honestly say that my face went a tad pale and there was a feeling of ummmm panic?  As she continued with the ultrasound we found out it was just one little squishy. Heart beat was strong 133 but amniotic sac was on the small size, like a week behind.  I think we would of been OK with that news but then the not so nice doctor with shitty bedside manners continues to say something about a 15% chance of miscarriage and that we need to repeat the ultrasound in 2 weeks and if there was something more I don't know because I just stared at K and tuned it all out. In 9 days we will go for our first actual OB appointment and hope and pray that little squishy is growing the way it is supposed to be. This is going to be a LONG 8 months..