im so scared! help

Hannah.
I go to my obgyn tomorrow and I'm scared I have endometriosis and me and my hubby are trying to get pregnant! But I haven't had my period since July 3 and almost 50 days late. And my dr have me pills to make me start bleeding and I have not started bleeding at all and I took pregnacy test and they are negative or at least they where a week ago when I went to the doctor. What?!?!?!?