Anovulatory Bleeding?

I've been off Yasmin BCP for 4 months now. The first month I ovulated on day 21, the second month on day 20, last month on day 16, and this month I had an annovulatory cycle, I never ovulated, I know because I take my BB temperature every morning and it showed no thermal shift. Today I started bleeding. Could all this be because of coming off the pill, wouldn't I have had problems right away, instead of 4 months later? Opinions please. Thanks