What if I have had my menstrual for seven days?

Lots of causes. This is a complex question. A number of different variables come into play - your age, the medications you take, your gynecologic history, your stress levels, etc. I am assuming your periods are usually less than 7 days. It is normal for menstruation to be variable. If the bleeding doesn't stop, or if your period remain erratic, seek care. Your doctor will be able to get to the bottom of it.