me and my partner did sex on 21st october.before 1 hour she took an unwanted 72 pill.after 2 days once very slight redish blood came out.but today on 28 th oct she noticed black blood spots and black blood flow.Is it dangerous???and the last period date was 14 th oct.so is it Period??but after today's pregnancy kit test the result was negative.how much period can be delayed????