TTC after Mirena IUD Removal

I had my mirena removed on 9/28/17. I had it in for a total of 9 years (I had a new on inserted after the first 5 years). I eventually stopped getting a period on it. since being removed I have not yet had a period. I have had sporadic days in which a very light brown sporting occurred. My husband and I are TTC and have been since removal. i just can't seem to pinpoint when I'm ovulating or when a period will come. I have taken a pregnancy test and several ovulating tests and it's always negative. please help!