Help, please! (Miscarriage??)

I need some hope in my life desperately. I got a call from my OB today with my hcg results. Stupidly I didn't get my numbers but she said I'm about 5 weeks along. Later on today I had light spotting to start...and then quite a bit of red blood, enough to look like a regular period. I'm completely freaking out. I went to the ER and had an ultrasound...nothing showed up but they said it could be too early to see anything. My HCG came back as 178 which they said on their scale doesn't add up to 5 weeks but my doctor could have a different number bracket. But I'll have to wait until Monday to find out. I'm loosing my mind. Has anyone else had semi heavy bleeding and went through with a healthy pregnancy?? Is there hope? Or is it just likely that I miscarried..?