You take care of yourself, if you need to cry, don't be afraid to let it out.
I've been in your situation twice.
One went one way, the other went the opposite way!
Last year, I had a MMC discovered at the 12 week scan, baby was there but no heartbeat. Needed surgery.
Three months later, at what should be 7 weeks pregnant, I had a little spotting, and something didn't feel quite right. EPU internal scan showed an empty sac, with no fetal pole, so about 5 weeks development. Had to wait a week to see if there was any growth. Growth was seen, but no heartbeat, and after another scan (at what should have been 9 weeks) there was still no fetal pole or heartbeat. More surgery followed.
Fast forward 3 more months, to late November, and I was rushed to hospital with bleeding, at what I was CERTAIN was 6.4 weeks pregnant. Scan showed an "irregular pod of fluid, consistent with a pregnancy of 4 weeks". I was convinced history was repeating itself.
One week later, being rescanned, there was a fetal pole and heartbeat, measuring at just under 6 weeks (I believed I should be almost 8 weeks by this point).
Two weeks after this, under consultant led care, I was rescanned, and baby was measuring at 10 weeks. We had a tricky pregnancy, with my waters going at 26 weeks, but DS was born at 34 weeks, and is now asleep on me, and teething!
The sizes are so small at this point, and it's all still to play for, embryos can 'catch up'. I hope for good news for you.