I have NO idea why a woman would become bitchy or grumpy while pregnant. I'M EXAGGERATING. My sister…

I have NO idea why a woman would become bitchy or grumpy while pregnant. I'M EXAGGERATING. My sister of 3 kids apparently was talking about me being this way. Seriously?! probably doesn't help when her 2 daughters are so disrespectful and she argues with them like they are her sisters not her children. I have anxiety, can't take any of my meds, and can't stand loud noises in confined spaces. thanks for reading my vent.