Had sex a week ago today period should be here this week. could i be pregnant. ?

Yes: at any time with unprotected intercourse it is possible to get pregnant. I would recommend that you perform store-bought pregnancy tests while abstaining from sexual activity. another option would be to visit your OBGyn or Family Doctor for discussion/evaluation. Again your period may or may not come because it is always a possibility that you can get pregnant. I wish you the best of luck !

It depends: It would depend if you had sex without condoms and/or contraceptives. If you have engaged in risky/unprotected sex, then pregnancy is always possible. Consider testing. Serum/blood HCG test is more sensitive/accurate esp early stages of pregnancy