I'm sixteen and I got my first period at 11. My period is usually 3-4 days and it's heavy but lightens as time goes by. I got my period for August around the 13th so I thought that was that. But yesterday I got my period again and it was the 26th. It was a medium flow. But then during the night it totally stopped. There was no blood in my pad, none when I peed, none when I wiped. It was gone. and it still is. I'm a little worried. Do you know what this may be?