I took plan B emergency contraceptive over 3 weeks ago. One week later, I had my regular menstrual period, then another week later I started a 2nd period. This bleeding was very light at first, more like spotting, but 3 days ago became very heavy. 2 days ago I passed a clot about the size of an orange, and have since been passing 3-4 golf ball sized clots. I have to change my feminine pad every 30 mins. The bleeding is heavier in the evening through to night time and just moderate-average through out the day.