Curiouser and curiouser

I got my iud almost two years ago, june of 2016, at my 8 week postpartum checkup. I was still bleeding heavily and erratically for a couple of months after insertion. Then I had almost normal periods for a few months, they were heaven, on time, shorter, easier (not lighter, but I never needed a super tampon in the first place). January last year everything changed. Suddenly they were erratic and irregular with spotting so bad it was like a second period. So I was bleeding twice a month. It was very light (1-3 heavy liner pads a day) but often the same length as before, both times of bleeding (5-7 days). Weird camps all over the place. Phantom baby kicks all over the place. Bloating that won't go away (I look 5-6 months pregnant all the time). October/November my periods were just one period in each month that was shorter (1-3 days). December and January they were heavier than "normal" before baby and the longest I've had (9-12 days). I know my iud was out of place in December as I could feel the strings outside my body, but it repositioned itself during that period and is back to normal.

Here's the curiosity.... my uterus is doing something very weird now, it feels like baby hiccups and poking and kicks, but I can't be that far along if I am pregnant. So far the period this month has been a couple of hours at most but with the worst cramps I've ever had (they were down to my toes).

Normal? Just weirdness? Or potentially worrisome?