I Was 12 Days Late On My Menstrual... Yesterday I

I was 12 days late on my menstrual... Yesterday i had a brown pinkish discharge... Today i have bright bright red blood. It feels like my period is really heavy, extreme cramping and ive cried over and over for no reason but when i wipe its less blood than a usual period i have. Ive tooken two hpt and they're both negative... Whats going on with me?