someone please help!!!!

Hi everyone myself and my boyfriend have been trying for baby number 2 for 3 months now and my cycle is currently at day 58...i have never went this long without having a period before except for my first pregnancy bit I took 3 tests and they have all came back negative! I don't know what's wrong with me. I have a doctor's appointment booked for Thursday so hopefully I can get some answers then.... any suggestions are welcome in the mean time lol :) thanks!