Although its normal to see an empty sac at 5 weeks.. they didn't warn you they might not be able to see anything yet? Also did they schedule you for a a follow up ultrasound? Usually it starts with an empty sac, then like a yolk sac then within the next week or so you'll be able to see a heartbeat.
I felt something wrong at 7 wks. I told the medical people. No one would listen. No one would scan me. At 3 months I went for my first scan and they found an empty sac saying the baby died about 7.5 weeks. I can't get over it. I am too old now although I still try I am disappointed every month. It is an awful thing and I feel for you. x