Weird

ok i had sex on september 12th , & my period usually starts on the 19th . yesterday i thought it was starting but when i checked it was brown blood , so i waited to see if any fresh blood would come & i didnt . but i woke up today & i had a mixture of brown blood a lil red blood & white discharge ? what could this be ? has this ever happened to you before ? what was the outcome ? did your period come ?