So i started taking birth control about a week ago without starting my period my last period was the beginning of september ...last night he ejaculated inside me but ive took the birth control pills 7 days every day prior to last night?

Depends on details: Hopefully, the birth control pills are working, but it's too soon to tell about pregnancy. A urine pregnancy test, done correctly, gives a reliable result 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a "period." If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test.