Re: Rising HCG levels but nothing on u/s...
I had the same thing happen to me twice. One had a good outcome and one a bad. The bad outcome had nothing until 6 weeks and then the sac appeared but nothing ever formed in the sac. BUT my HCG levels were checked a third time and by the third time were no longer doubling within the 72 hours. They did continue rising. The good outcome had a sac finally appear at 6 weeks. 6 weeks 4 days still a sac. Finally at 7 weeks 2 days baby with hb. I think you are really too early to see anything except the thickening. Try not to worry too much even though I know from experience it is so hard!