help! let me know if someone has been through this please!

I went in for my 6 week ultrasound on 2/1/17. Went in today for my 9 week appointment and they couldn't find the baby this time. I had to go to emergency for a stat ultrasound and still haven't gotten my results. I haven't had any bleeding or cramps... has anyone experienced this? Help anything would be nice I'm worried. They seen the yolk sac but not the embryo.