Weird "Period"

Aubrey
This cycle, I was supposed to start Dec 31, but had cramps every single day after ovulation. Starting Dec 28, I spotted very lightly (only while wiping), then had one semi-heavy day on Dec 29. Then, nothing, but this morning, I woke up with pretty bad cramps but still no bleeding.
Usually, my period is irregular so there's so surprise there but I usually spot for 1 day, have an insanely heavy day on the "second" day, and normal period for the next 3-4 days.
Anyone have any experience with something like this? I tested neg on Dec 24.