bleeding after sex

This is only the second time i've had sex, but i didn't bleed the first time.
I'm wondering if I should be worried.
It is light bleeding currently, but I'm expecting my period soon, so it could be that, too.
I usually get my period the 19th of each month (today is the 17th).
Could having sex make your period come sooner?
Or would getting my period 2 days earlier than usual be normal?

Thanks!