Waiting..

So i went to the doctor two weeks ago for an ultrasound thinking we were almost seven weeks. After only seeing a sac and yolk, the measured me at more a little under six. Went back today and there has been little to no growth, still now visible baby or heartbeat. We talked about how this might end in a miscarriage and i was a mess as it would be our second one. However just got a call from the doctor that my hcg levels are in the 34,000's which a good number and that maybe we just had all the timing off. The last time we had sex was august 21st (last day of our honeymoon). Could it be possible that the timing was just all off? I dont want false hope