SERIOUS QUESTION

is it possible to have sex a week before your period. then you get a period, can you still be pregnant? 
So basically, we've been having unprotected sex for about 3 weeks straight. Just because we love sex lol I got my period Friday night, that Friday morning we had unprotected sex. My period was regular. A few days late but regular. & I haven't had sex since I've gotten my period. Is it possible I COULD be pregnant?? I have all these symptoms & it's driving me crazy.