After having contact, if a girl bleeds and her periods are due the very next day, but she doesn't have periods on time. As in this case, she noticed blood on 14th night, and her periods were due on 15th, but till 18th she doesn't have periods. What does this means. She is a thyroid patient as well and usually always overdue with period date. On 15th morning she noticed brief mucus with few stains of blood. She checked with urine strip test (pregnancy), which is negative. Now what to do. Should she consult any doctor or still wait? Please help.