9 days past ovulation i had intercourse and later noticed i had slight bleeding, now i am 11 days past and bleeding is heavy. what could this mean?

A period?: If you are 11 days post ovulation with bleeding then the most logical conclusion is that you started your period a few days early. Track your cycle over the next few months. If you find that you are always irregular then schedule a visit with your obgyn to discuss cycle regulation.

Delayed period: Late period. However pregnancy test will be helpful to rule out an early abortion.