How do you know if you’re miscarrying?

I’m six weeks and two days and I’m high risk because of a chromosome mutation thing. I haven’t really had any nausea except a couple times that came and left pretty quickly and that was last week. I’ve had sore boobs since before I tested positive for pregnancy. And I’ve had light cramps on and off (no bleeding) and I’ve had heartburn most of the two weeks I’ve known so far. I just don’t FEEL pregnant the last few days. I haven’t had heartburn the last few days and I feel like my boobs aren’t as sore. And like I said I haven’t been nauseous yet. I have my first Obgyn appointment next week June 4 so I guess I have to wait until then to know :( but I can’t tell if I’m just paranoid or if the baby has stopped growing. I haven’t had any bleeding and no severe pain or bad cramps. Anyone had their embryo stop growing? Is this a missed miscarriage?