Period or implantation bleeding

So im on the pill but i keep missing doses of it and i thought my period started today but its light and brown. Which it never is. Its has always started off really heavy and bright red right away. And I usually have cramps and this time i dont have any at all which is weird. So does this look more like the start of a period ( i know brown blood is old blood and can be normal). Or more like implantation bleeding