Y can't I get pregnant?! ?

This is our first time TTC and we've had no luck. I've been off OCPs for about 10 months and actively tracking menstrual cycles and fertile days for about 5 months. I was hoping so much for this cycle...It Would've been a perfect holiday gift to surprise my family w baby news. I've taken 3 tests last week.. All negative, period due tomorrow, we'll see If it comes or not. My menstrual cycles have been super irregular though  -- any ideas or experiences why the irregularity and lack of success?! Each negative test feels like a mini failure -- and I'm a type A go-getter, "there's nothing I can't do" kind of person -- this is killing me!