Help!

Ok, so I will preface this with saying that I have severe anxiety. I had to go to the ER yesterday bc I was having severe pain in my back, neck, and lower abdomen, along with extreme nausea, vomiting, and diarrhea. I had both a regular ultrasound, and a transvaginal. No heartbeat was found, but they said after measuring the fetus, I'm only 6 weeks, 1 day along instead of the 8 weeks I should be according to my conception date, lmp, and the bloodwork I had done at my doctor's office. Is this normal? Does this mean something is wrong with my baby? I have an appointment with an ob-gyn Monday for my first prenatal appointment, but after how I was treated at the hospital yesterday (long story short, they were extremely rude and neglectful) I won't be setting foot in that hospital again. Unfortunately, the ob-gyn I set up recently only delivers at that particular hospital. Anyway, can anyone offer advice? I'm freaking out that something is wrong right now.