I am so confused and would appreciate any insight. So thank you in advance for reading this!

We have been TTC for months and it’s been really hard on me not getting pregnant. I am like clockwork with my periods every 28 days. I know when I am ovulating and it is the same time every month as well. This month at 8dpo I started spotting. I thought maybe it was implantation bleeding. It was light and pink. I continued to spot only when I wiped everyday for 4 days. And now I have been heavily bleeding with clots for 3 days. From 8dpo on I have had pretty intense cramps. I tested once and it was negative.

Does this sound like a very early period? I have always had very consistent cycles and have never experienced a period a week early. Not sure if it could have been a chemical pregnancy. Thank you for any insight!