nervous for my first scan

This is my first pregnancy, it took me over a year to conceive, so it's still a little hard for me to process I'm pregnant (I've bought a million tests lol). I have an early scan booked for Tuesday and I feel sick with worry, I just don't want to feel like I was wrong for telling everyone that I'm pregnant when I'm not. I think all of these feelings have to do with me being in disbelief about the whole situation. Is there any way I would know if I had a missed mc?