Late by 19 Days

Hello everyone. I'm 22 and engaged to the love of my life. I am still a little new to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a>. I have been late for my period by 19 days. I have taken two pregnancy test at a physicians office (my job) which came back neg. I have also taken one from a local drug store. I'm having excessive urination some nausea. I've noticed a lot of pressure in my abdominal area. I'm going through some stress in my life. Any thoughts or suggestions before I see my GYN.