am i pregnant?!?!

im on the pill and i stupidy had unprotected sex, he had already came twice but he said he came a little bit inside me. he said it was only a little bit and i am on the pill and now my period is a day late, what should i do?!?! should i be scared?? im only 16 and both of our parents are super religious they can never know we had sex before marriage! do you think im pregnant? what can i do?!?! is there any way to make my period come?!?