Unusual period or early miscarriage

[Acat22]

So, I'm not sure if this it the right category or not and sorry for tmi.. my periods usually last 5 days, sometimes 4 days but never any longer and I have light to medium flow and never fill a pad between changes.

I started my period 9 days late which is not uncommon for me but the last couple of cycles I have been regular. This cycle started with dark brown blood which was mainly spotting which I never get, it gradually got heavier with some clotting which the amount I had was unusual. It calmed down on day 6, day 7 I was really heavy and filling a medium pad every 4 hours. Day 8 (today) I barely had anything then all of a sudden had a gush of blood with clots. I've not really had any bad cramping but I'm extremely tired. A Google search hasn't really helped me so thought I'd post here to see if anyone had anything similar? Everything about this period has been unusual and an early miscarriage never really crossed my mind until this recent gush of blood.