First Ultrasound is Tomorrow

Tomorrow my husband and I go up for more bloodwork and our first ultrasound.  I'm scared.  I'm terrified.  I really don't want to have gotten this far and then tomorrow find out there's a yok sac but nothing in it.  Or anything else horrible they could say.  I haven't been sleeping well because I can't get comfortable and I can't turn my mind off.  My pants no longer button.  I'm nauseous and tired.  What if all of these side effects are all for not?! 
We've told our families already, and what if we have to go back and tell them, "Nevermind, the baby or babies didn't grow right so we're not pregnant any more". 
If all is well, we'll find out how many are in there (we put 2 in) and when our due date should be.  I'm praying so hard for great news.  I also hope my bloodwork is continuing to rise and indicate great things.