I'm 16 I've had my period since I was about 11 My normal periods are really heavy and last 7 days This month It lasted for 10 days straight and it was really heavy, well for a day or so it stopped completely then I woke up the next morning and it was back heavy and with lots of clots, a few hours later it stopped completely again, well today I woke up and it was back really heavy with lots of clots again. Why is this happening?