Ok I can relate to this question. (Kinda). I was just pregnant and I really think that stress can cause a miscarriage...but I'm not 100% sure about it...
today I just found out I had a miscarriage..
My dad and I fight all the time and his girlfriend and his daughter. My boyfriend and I don't fight at all..(Sometimes just little arguments but that's not a big deal).
I was fine until I started arguing with people...but don't get me wrong you can also have a miscarriage for many other reasons too.
Stress I think is #1.
Just try relax and stay calm about things...that would be my best guess.