What is the reason for bleeding with clots during the 6th week of pregnancy?

It is always difficult to pinpoint the exact cause of bleeding in a first-trimester pregnancy. It could just be bleeding from the cervix or the edge of the placenta ( which is bigger and more close to the cervix because of the twin pregnancy ) and these situations generally bear little or no significance. Sometimes the bleeding can carry on up to the second trimester. If the heartbeat is present, the same still holds i.e. over 97% of the time the pregnancy will carry on unharmed. In the old days, any vaginal bleeding in the early part of pregnancy is called ' threatened abortion '. With the advent of Ultrasound, we have to say this is a misnomer, as in the cases when the fetal heartbeat is seen, the pregnancy is not ' threatened '.