I’m bleeding 2 weeks early, not nearly as much as I usually do

first 3 days: dark brown blood, light pink when wiped but mostly dark brown

yesterday evening/night: still brown on pad, but more red when wiped and dripped a bit (it did not fill the pad as much as it usually does, only 1/4 of what my period usually does)

today: this morning it was bright red in the toilet, and I didn’t bleed much during the night as much as I usually do, it was red when I wipe but on my pad it is a dark brown

is it brown because the blood has oxidised and there isn’t as much fresh blood coming out consistently (lighter flow?) causing it to look brown instead of the red?