Go find another ob/gyn SOON to get a second opinion, and report this f*cking quack to the AMA. I had early ultrasounds with both of my babies, and neither of their heartbeats showed up until about 7 weeks. With my second baby, I had an ultrasound at 6 weeks, and there was a yolk sac, but no fetal pole. All it took was a week, and there he was! Did this dr. do a trans-vaginal ultrasound? (They do them early in pregnancy because they get a much closer/better look at the baby.)
With my first son, my ultrasound showed some type of mass on one of my fallopian tubes (and also a yolk sac in my uterus. He thought I might have had twins and one was ectopic). Even though I was having NO pain, no fever, no indication that anything was wrong, this doctor was trying to convince me to have surgery to have see what this mass was. He said there's a 75% chance I could lose the baby I had in my uterus. He even had a group of specialists come in and talk with me. I promptly thanked them for their time, got up and walked out of the office and out of the hospital. 8.5 months later, I had a healthy, happy 8 lb. 4 oz. NON deformed baby boy who is now the light of my life, along with his younger brother. :) This idiot doctor tried to convince me that the baby would also have deformities since I am epileptic and take a seizure medicine. Do you have ANY idea how incredibly grateful I am that I didn't listen to him?
Please..do yourself and your baby a favor, and DO NOT go back to this man. Get a second (and third, if necessary!) opinion.