Had unprotected sex a week before my period was suppose to come when it was time it never came and i had a negative preg test could i be preg still?

Maybe. Maybe not.: Pregnancy is a common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially birth control pills), hormonal disorders, etc… If worried, one can repeat a home pregnancy test one week later. There is no need to repeat before then.