Hello...... There wouldn't be significant growth at 6 weeks... Suprapubic bulge appears at 12 weeks... There after you can witness growth of fetus.... Wait for another one or two weeks... If ultrasound fails to detect heart beat it could be miscarriage... Consult your gynaecologist.
Hi dear.. You have to repeat your ultrasound scan after 7 days. If still then heart beat is not seen , it's most probably a non viable pregnancy.
Usually when the gestational sac in ultrasound is more than 25 mm but still fetal heart is absent,, or when CRL is more than 15 mm but heart is absent, then pregnancy is non viable. In such situations pregnancy will not continue.
Also I will like to know whether your ultrasound mentioned a proper fetal pole and a normal yolk sac. If fetal pole is not seen, it's a blighted ovum.
I hope your repeat scan will be normal. But if it's not all good, that doesn't mean your next pregnancy will meet the same fate.
But in case this becomes recurrent, go for one Karyotype test( chromosomal study) of both partners.