I have had irregular periods since I was 11, but not like now. Early last year I got off BC while my husband was away (military), but I didn't have my first period until July, which was actually when I decided to get back on BC. It was very light and only lasted a couple days. That cycle was 35 days. Then I stopped my BC when DH decided he wanted a baby too. But since then (August) my cycles have been 38 days, 19, 57, 45, and I'm currently on CD 22 this month... The latter two cycles were started with 10mg Provera.
My doctor told me I am not ovulating so this cycle I am also on my first cycle of Clomid. Seems to be working as I'm getting positive OPKs for the first time ever! Fingers crossed!
Also, do you have PCOS? That is what I have. I'm working with my OB closely and I think that's what's helping me. I'm also temping, using OPKs, and saliva ferning. It's really hard to know when you're ovulating (and, in my case, near impossible to ovulate at all) when you have irregular cycles. I wish you the best of luck! And I hope you can find something that works for you!