6 weeks 2 days no heart beat ?????

This is my second pregnancy first ended in miscarriage due to two sperms entering one egg a little before 5 weeks on my current pregnancy i started spotting and three random gushes after the first i rushed to the er then to my ob the next day baby was 5 weeks 2 days no heart beat because it was to early had three hcg tests first 5000 two days later 10000 four days after that 21800 went to my 6 week appointment and there was no heart beat but baby measured at 6 weeks 2 days like it should and baby is still really high in my uterus they want me back in a week to look for a heart beat if there isn't one they want to do a d&c; on monday i wont do a d&c; till im sure my baby is no longer growing has any or did anyone else have trouble hearing a heart beat this early?