Hi. I'm 17 years old and I had my period December 2nd through the 6th. I stopped taking my birth control on the 12th and had unprotected sex twice. And today, December the 15th, I've been bleeding like a period. At first it was very light pink, and it will go to solid brown now it's red and sort of brownish. Any reason I could get my period 9 days after my last period????