Implantation bleeding

So I made a few a post a few days ago about possible implantation bleeding. My period is usually on time and last about 4-7 days and is always super heavy. Well since I’m working teaching kids I can’t go to the bathroom frequently to change my pad so I’ve been putting a tampon in. And each time I take it out it’s not much blood. I usually bleed through my tampons and it’s always super red. Well Sunday I started bleeding some, and it mainly shows up when I go to the bathroom and when I wipe it’s a light red. And when I take the tampon out its been brown and hardly red. And now the bleeding has almost completely stopped. I wasnt suppose to start my actual period until today and now there’s almost no blood. Could this be implantation bleeding or just a shorter and lighter period??