This month for some reason my period is brown with some Red... I am 17 and I am sexually active although I've only been with only 1 guy for the past 3 years... so I kind of ruled out STD's... what could it be. Please help... :( I'm scared!

Brown blood is old blood. I have this every month - toward the end of my period. I have asked my dr. about and she says that it is normal. Now, I have never had it that way from the beginning to the end - it's just the last 2 or 3 days.