Went for my diet prenatal today. Based on my last menstrual I was suppose to be 5wks 5days today. Doctor first thought I was measuring 8-10 weeks along. Went and had ultrasound done and couldn't see a sac. Then had a vaginal one done and still couldn't see anything. Went and did blood work after and my HCG levels were 561. If they don't double on Friday when I go back for bloodwork she said it would be classified as a miscarriage. Has anyone experienced this? I am so worried and so scared.