Irregular Periods

Jodie
I've never had regular periods apart from when I'm on the pill, I did have a scan two years ago and everything was normal, but i've been off the pill for about two years now and there's no rhythm to them or anyway to predict them, it's about 2 or 3 a year but I had a 3 week one a couple of months ago. Has anyone else heard of anything like this before or have the same issue?