Could I Be Pregnant If I Had Unprotected Sex On The Last Day Of My Period And My Next Period Is Now 6 Days Late?

i had unprotected sex on the last day of my period which was march 13. the guy didn t ejaculate. i was supposed to get my period again april 7 but it s april 13 now and it s 6 days late. my period was early last month but sometimes it can be a couple days late or early. is there a chance i could be pregnant?