I agree with you all, that I always thought I was very irregular because I was diagnosed with PCOS at age 18, but after my surprise pregnancy at 23, it turned out I was fertile, and when my husband and I decided to get pregnant with #2, I realized that I was ovulating more often than not, and that was usually between day 18-24, a pretty big gap!
My DH and I wanted to try to get pregnant shortly after we were married. I was on BCP for 7 yrs before that so I had stopped them the month we were married my cycles were all over the place and I remember looking online and seeing something about the book "Taking charge of your fertility" I read the book learned how to chart and got preggers pretty quickly its a good thing I was charting though and new what to look for I had O'd on day 40 of that cycle and had a 16 day lf. After my first pregnancy my cycles went to clockwork 29-30 day cycles almost always ovulating on day 15 with a 14/15 day LF.
Using charting to my advantage this go round trying for a girl