Implantation 5dpo or just crazyness?

Yesterday I was on cd 21. I felt really tired but I can chalk that up to getting up early.... anyways, I layed down for a nap and felt some cramping. It was mostly mild but still enough for me to think wow my period is about to start! Which is unnormal for me I usually have a 29 day cycle. After I woke up I used the bathroom and when I wiped it was a very light pink color with what appeared to be a few teeny tiny red blood clots. Like the size of a piece of quinoa before you cook it. Then I got some lower back pain and the mild cramps continued but when I wiped for the rest of the evening there was no more light pink only clear cm with like 3 more of the tiny blood clots and then they were gone and haven't had any since..... I'm pretty sure I ovulated on cd 16 so that would make yesterday only 5dpo. Is that even possible for implantation to be that early or does it sound more like a cyst burst or something? Help?