Need your opinions plz!!

Hello ladies i was wondering if i can get some help hear..

I had ovulated on the 4th of sept. And i had intercourse 5days before my period would start. My period was late an very heavy. 11days after we had intercourse we tryed again during this Octobers ovulation an as i used the restroom after i seen a thin streak of blood probably as small as a papercut thin..

Im confused i did have intercourse 5days before a super heavy period could that day be possible?

Or do u ladies think it was a strek of blood that happen from having intercourse?