It sounds like peri to me, although best to get checked out, although I never did, I just knew it was 'peri'.
I was very regular and then one month I came on 1 week early, and it all started from there.
My periods were all over the place, light spotting to flooding, with or without clots, each lasting from a few days to weeks at a time, once I had one for a few months, it just wouldn't go! My cycles were anything from about 2 weeks to months at a time also.