Hcg levels & Blighted Ovum

I am so frustrated...went in for my first scan on 11.25, only a gestastional sac was seen, no yolk or embryo, lmp was 10.12.19 but they had never been consistent since I had a D&C back in late April. HCG levels on 11.25 were 9697, fast forward 48 hours and my levels on 11.27 were 13179 (a 36% increase which is indicative of a viable pregnancy). So had a follow up scan yesterday 12.5, and again just a gestational sac, no yolk...went for another blood test to check my levels and my hcg was 33671. The doctor has me going in tomorrow for another blood test to check my levels again. She said that she would definitely have me go to the hospital to have the imaging dept do an ultrasound so that she has a second set of eyes to look around. She checked all around my uterus and my tubes and saw nothing...could it be possible to still be pregnant?? I have had no cramping, bleeding, pain, spotting, etc and my numbers are doing exactly what she wants to see them doing. Any insight, thoughts?? Are babies really good at hiding? I am in rural Maine and I question the ultrasound machine strength...hmmmmm