What Causes Pink Discharge After A Sexual Intercourse?

brown then to light pink discharge after period/after sex
LMP 10/17/12.. after period ended had gooey brown discharge, which has now changed to a very pale pink to clear discharge only wen i wipe.. no odor.. and i have had sex after period.. and now feels like a yeast infection is coming on.. but i am prone for BV as well but theres no odor with the discharge .. i had my tubes tied may 14th 2012 so doubting implantation what should i do? is this cause for concern?