Miscarriage

So had our first ultrasound last Wednesday and the sac and whatnot is measuring at 8 weeks, but the baby is only measuring at 6 weeks. Heart rate was only 70 as well. The doctor was pretty straightforward with the fact that this may be a miscarriage. We have another appointment this Friday to see if there is any growth. With my first I was only nauseous for a few weeks, and I'm not feeling nauseous anymore with this one...not sure if that's good or not! I'm trying to be positive and calm, but of course Google got the best of me and sooo many people have had this happen and it definitely resulted in a miscarriage. I'm not sure what I'm looking for...support, commons stories (good or bad outcomes), etc. I guess I just want the truth and what to expect. Will I know if I'm having a miscarriage? Thank you so much ❤️