Pregnancy hormones!!!!

So according to this app I am 3 weeks and 2 days pregnant. Ever since last night, going into today I have been SUPER emotional. I've never been so upset over the littlest things in my life! One minute I get so mad over something my boyfriend says even if its not offensive then the next minute I'm crying in a ball not knowing why I'm so sad. Is it normal to be so emotional so early on? How early on in your pregnancy did you start feeling the horrible emotional change? Any advice on how to get through it ?