i use birth control, i have the depo shot and have been on it for about 2 /12 months now. me and my bf have sex maybe once every week, im scared because sometimes after sex i will bleed but i know why i am , today i was usuing the bathroom i noticed brown discharge in my underwear, i whiped it off with toilet paper and noticed a bloody tint . is this normal, not just using depo but for any birth control? or is this something to worry about..