Worried sick about 7w ultrasound.

Jennifer
I seriously cannot stop worrying. This has been going on for 2 weeks. My beta hcg at 13dp5dt was 396 and at 16dp5dt it was 774. That's a 74 hour doubling time, isn't that a horrible sign? My doctor said everything looked great. I'm so confused. I'm terribly afraid of a blighted ovum, ectopic or missed miscarriage. I don't see how my pregnancy can last.