Miscarriage No sac at 6 week scan after being reassured after a few hours bleeding episode

I have been through 7 transfers all implantation failures until I switched clinics and got a new cohort of embryos. The first transfer stuck and betas were beautifully progressing. I was even told the way my numbers were trending meant the embryo was superb. At my 3rd and last beta I had brown to light pink spotting that stopped and i notified my clinic and was told it was normal and in just 2 days my hcg went from 1491 to 5041. 2 days later I had bleeding with a few clots and I rushed to the er when I didn’t receive a immediate answer from my ivf nurse. she called while I was on the way and told me they see this often and its more than likely a hematoma and I can still go to the er if I just needed reassurance. I got there and they took my hcg and did an ultrasound. hcg had went up to 11,146 and ultrasound showed a 3.9mm gestational sac or so they said. They sent me home and said everything looked reassuring and I was early at 5 weeks 2 days and wait for my scan at my clinic. well that day came and I was officially 6 weeks and thought all was well but when the ultrasound was done NOTHING was there. I thought it was a joke and all my doc could say was it looks like a miscarriage. my hcg had fell to 641. Im so gutted i have no words and feel i have no idea what direction to take. my embryos were not tested because im fairly young. Froze 21 well graded embryos. Im just holding on to hope of trying again. I have done so many test over the years of this. and to finally get implantation and it crushes like this is devastating.