Hello, Anon! Thank you for posting.
For the first few years after menstruation begins, long cycles or irregular periods are common. In other words, your period might not always be the same each month. Our hormones dictate our periods. An occasional heavy period with clots is usually nothing to worry about. It's normal to feel scared if this is the first time you have experienced this. Is the bleeding still heavy? If so and you are still concerned, you should see a doctor. Otherwise, try to relax if it seems to be winding down. Is there some reason you have not told your parents or at least your mother you have your period?