What could it mean??? (WARNING: tmi)

So, my period ended 6 days ago. This morning as I was leaving work I felt slight cramping in my lower left side of my abdomen. About an hour into work I had to go to the restroom.

TMI ahead!:

When I looked at my mini pad there was a small string of bright red blood. Like very small. I thought it might have been maybe from my towel, from after I showered in the morning, but I touched it and it was clearly a small clot of blood.

Later on in the day I went to the bathroom again and there was nothing. About an hour later though I went again and saw light pink again on my mini pad.

I’m not sure if this may because my hormones fluctuating or what. My breasts also seem to be a bit tender at times. I had thought I was pregnant a week before my period started because I was so sick and thought I had had implantation bleeding. My period started two days early and the first day I have really weird light pink blood.

My period was normal and I took a pregnancy test after it ended any way just in case and it came back negative.

ALSO my discharge is normal. I’m healthy down there. No change there so I’ve ruled out infection.

So, has anyone had this happen or anything similar happen in that past or recently? If so what could it be? Why might it happen? Do I possibly need to take another pregnancy test?

Thanks 😊