is this considered the first day of my period?

I know real red blood would be the first day but my period just started and started kinda odd, different than usual. firstly it started on time but I went through extreme craps and it couldn't even be considered spotting. that was yesterday so I wasn't considered first day. but then today I woke up with the worst diarrhea, alllll dayyyyy. I've taken a ton of Pepto bismo and it's legit done nothing. I took advil for the pain though and that helped.

anyways I have to walk to work and I had a feeling of getting the heavy shed while walking so I used a regular tampon that lasted until after work (4 and ½ hours) so I assumed I probably didn't fill at all when I came home though turned out It was full (not leaking) but since then I haven't been bleeding heavy at all. but since it managed to fill up one in 4 hours (mostly dark brown and some red) [SORRY TMI] Is it considered my first day?