I had a tibial ligation 8 years ago and my menstruation always have been on time and last 5 days only now I got off and now I'm back on and cramping now a little. And I'm a anemic as well.

It's possible that you are pregnant, but not probable. If you are, most likely it would be a tubal pregnancy. I recommend contacting your doctor.

Menstrustion is dark red and now its flowing like a period. Should I wait then see a doctot

How long have you been off your period and what is your age please?