Bleeding after sex...?

So me and my boyfriend had sex like 3 days ago and right after I started bleeding a little bit. Then the next day it was heavier and it's been that way for the past two days. It's like brownish red, and it kinda stings down there now.. What should I do? Should I be worried or wait it out? Am I just spotting heavily because he hit  my cervix, did it trigger my period early?