What does it mean when you have unusually bright red menstrual blood with big clots in it and it came 4 days late?

Probably nothing, but could be a sign of infection. If the blood clots have a white center, you may have miscarried. If you miscarried though it would be very painful and you'd fill more then 2 super maxi pads in 2 hours. My period has blood clots all the time and I am healthy- my gyn said that's normal.